I needed to google it becouse there is no such options on my VirtualBox. TBH I use v5 of VB and I don’t know if this is a version or hardware releated option.
I skimmed through the log and this is the part when VM go bad:
00:00:36.419029 VMMDev: Guest Additions information report: Version 6.0.10 r132055 '6.0.10_Debian'
00:00:36.431640 VMMDev: Guest Additions information report: Interface = 0x00010004 osType = 0x00053100 (Linux >= 2.6, 64-bit)
00:00:36.433272 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:00:36.451509 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:00:36.455432 VMMDev: Guest Additions capability report: (0x0 -> 0x0) seamless: no, hostWindowMapping: no, graphics: no
00:00:36.481552 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:00:36.481641 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:00:36.520905 VMMDev: Guest reported fixed hypervisor window at 000c1400000 LB 0x400000 (rc=VINF_SUCCESS)
00:00:36.540165 VMMDev: vmmDevReqHandler_HeartbeatConfigure: No change (fHeartbeatActive=false).
00:00:36.554566 VMMDev: Heartbeat flatline timer set to trigger after 4 000 000 000 ns
00:00:36.573544 VMMDev: Guest Log: vgdrvHeartbeatInit: Setting up heartbeat to trigger every 2000 milliseconds
00:00:36.754670 GUI: UISession::sltAdditionsChange: GA state really changed, notifying listeners.
00:00:36.759242 GUI: UIMachineViewNormal::adjustGuestScreenSize: Adjust guest-screen size if necessary.
00:00:36.770881 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:00:36.770960 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:00:36.790733 VMMDev: Guest Additions capability report: (0x0 -> 0x0) seamless: no, hostWindowMapping: no, graphics: no
00:00:36.797107 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:00:36.805652 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:00:36.838341 VMMDev: Guest Log: vboxguest: misc device minor 58, IRQ 20, I/O port d020, MMIO at 00000000f8400000 (size 0x400000)
00:00:54.560727 VMMDev: Guest Log: vboxsf: g_fHostFeatures=0x1 g_fSfFeatures=0x0 g_uSfLastFunction=20
00:00:58.980307 VMMDev: Guest Additions capability report: (0x0 -> 0x4) seamless: no, hostWindowMapping: no, graphics: yes
00:00:58.997404 GUI: UISession::sltAdditionsChange: GA state really changed, notifying listeners.
00:00:58.997507 GUI: UIMachineViewNormal::adjustGuestScreenSize: Adjust guest-screen size if necessary.
00:00:58.997610 GUI: UIMachineView::sltPerformGuestResize: Sending guest size-hint to screen 0 as 1024x696 if necessary
00:00:58.997690 VMMDev: SetVideoModeHint: Got a video mode hint (1024x696x32)@(0x0),(1;0) at 0
00:00:58.997759 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:00:58.997821 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:00:59.423326 VMMDev: Guest Additions capability report: (0x4 -> 0x0) seamless: no, hostWindowMapping: no, graphics: no
00:00:59.426104 GUI: UISession::sltAdditionsChange: GA state really changed, notifying listeners.
00:00:59.426725 GUI: UIMachineViewNormal::adjustGuestScreenSize: Adjust guest-screen size if necessary.
00:00:59.426968 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:00:59.427321 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:00:59.486253 VMMDev: Guest Log: 17:25:36.443365 main VBoxService 6.0.10_Debian r132055 (verbosity: 0) linux.amd64 (Aug 21 2019 16:12:14) release log
00:00:59.486418 VMMDev: Guest Log: 17:25:36.443646 main Log opened 2019-11-25T17:25:36.443200000Z
00:00:59.544258 VMMDev: Guest Log: 17:25:36.501359 main OS Product: Linux
00:00:59.562657 VMMDev: Guest Log: 17:25:36.520430 main OS Release: 4.19.0-6-amd64
00:00:59.583357 VMMDev: Guest Log: 17:25:36.541157 main OS Version: #1 SMP Debian 4.19.67-2+deb10u2 (2019-11-11)
00:00:59.584672 VMMDev: Guest Log: 17:25:36.542540 main Executable: /usr/sbin/VBoxService
00:00:59.584779 VMMDev: Guest Log: 17:25:36.542542 main Process ID: 505
00:00:59.584869 VMMDev: Guest Log: 17:25:36.542544 main Package type: LINUX_64BITS_GENERIC (OSE)
00:00:59.597844 VMMDev: Guest Log: 17:25:36.555725 main 6.0.10_Debian r132055 started. Verbose level = 0
00:00:59.747108 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:00:59.747376 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:01:00.041715 VMMDev: Guest Log: 17:25:36.840254 main vbglR3GuestCtrlDetectPeekGetCancelSupport: Not supported (#3)
00:01:00.044212 Guest Control: GUEST_MSG_REPORT_FEATURES: 0x1, 0x8000000000000000
00:01:00.155362 VMMDev: Guest Log: 17:25:37.113160 timesync Error: vgsvcTimeSyncWorker: VbglR3GetHostTime failed; rc2=VERR_NOT_SUPPORTED
00:01:00.239760 GUI: UISession::sltAdditionsChange: GA state really changed, notifying listeners.
00:01:00.239951 GUI: UIMachineViewNormal::adjustGuestScreenSize: Adjust guest-screen size if necessary.
00:01:00.240073 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:01:00.240181 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:01:04.459415 VMMDev: Guest Additions capability report: (0x0 -> 0x4) seamless: no, hostWindowMapping: no, graphics: yes
00:01:04.459843 GUI: UISession::sltAdditionsChange: GA state really changed, notifying listeners.
00:01:04.459987 GUI: UIMachineViewNormal::adjustGuestScreenSize: Adjust guest-screen size if necessary.
00:01:04.460118 GUI: UIMachineView::sltPerformGuestResize: Sending guest size-hint to screen 0 as 1024x696 if necessary
00:01:04.460241 VMMDev: SetVideoModeHint: Got a video mode hint (1024x696x32)@(0x0),(1;0) at 0
00:01:04.460354 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:01:04.460489 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:01:04.471001 VMMDev: Guest Additions capability report: (0x4 -> 0x0) seamless: no, hostWindowMapping: no, graphics: no
00:01:04.471350 GUI: UISession::sltAdditionsChange: GA state really changed, notifying listeners.
00:01:04.471484 GUI: UIMachineViewNormal::adjustGuestScreenSize: Adjust guest-screen size if necessary.
00:01:04.471662 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:01:04.471777 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:01:09.510954 VMMDev: Guest Additions capability report: (0x0 -> 0x4) seamless: no, hostWindowMapping: no, graphics: yes
00:01:09.511388 GUI: UISession::sltAdditionsChange: GA state really changed, notifying listeners.
00:01:09.511532 GUI: UIMachineViewNormal::adjustGuestScreenSize: Adjust guest-screen size if necessary.
00:01:09.511661 GUI: UIMachineView::sltPerformGuestResize: Sending guest size-hint to screen 0 as 1024x696 if necessary
00:01:09.511785 VMMDev: SetVideoModeHint: Got a video mode hint (1024x696x32)@(0x0),(1;0) at 0
00:01:09.511895 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:01:09.511998 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:01:09.522410 VMMDev: Guest Additions capability report: (0x4 -> 0x0) seamless: no, hostWindowMapping: no, graphics: no
00:01:09.522748 GUI: UISession::sltAdditionsChange: GA state really changed, notifying listeners.
00:01:09.522873 GUI: UIMachineViewNormal::adjustGuestScreenSize: Adjust guest-screen size if necessary.
00:01:09.522972 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:01:09.523074 GUI: UIMachineLogicNormal::sltCheckForRequestedVisualStateType: Requested-state=0, Machine-state=5
00:01:10.176181 VMMDev: Guest Log: 17:25:47.134070 timesync Error: vgsvcTimeSyncWorker: VbglR3GetHostTime failed; rc2=VERR_NOT_SUPPORTED
00:01:14.559602 VMMDev: Guest Additions capability report: (0x0 -> 0x4) seamless: no, hostWindowMapping: no, graphics: yes
Those last lines are repeating in a loop until I kill machine by Ctrl+H.