there are a few similar problems reported here, but not mine exactly, so I dare posting this. (;
My set-up: Qubes 4 latest, Whonix 15 fresh install, Qubes VPN Proxy appVM/qube (Debian 9) fresh install (https://github.com/tasket/Qubes-vpn-support), OpenVPN via TCP file from Provider
This set-up worked flawlessly with Whonix 14, with UDP.
Completed every step here: https://www.whonix.org/wiki/Tunnels/Connecting_to_Tor_before_a_VPN
The VPN qube works fine everywhere, Tor via sys-whonix/whonix-15-gw works fine – just anon-whonix resp. whonix-15-ws resp. Tor Browser can’t connect.
Output from whonixcheck in anon-whonix:
[INFO] [whonixcheck] Qubes qubes-db Test Result: Connection to local qubes-db daemon succeeded, ok. [INFO] [whonixcheck] Qubes Settings Test Result: Ok. (GATEWAY_IP: 10.137.0.9) [INFO] [whonixcheck] Qubes Settings Test Result: Ok, qubes_vm_type is AppVM. [INFO] [whonixcheck] Check Kernel Messages Test Result: Found nothing remarkable, ok. [INFO] [whonixcheck] check network interfaces Result: Ok. [INFO] [whonixcheck] Check Package Manager Running Result: None running, ok. [INFO] [whonixcheck] Tor Check Result: Not running on Whonix-Gateway, ok. [INFO] [whonixcheck] Tor Config Check Result: Tor config ok. [INFO] [whonixcheck] Tor Pid Check Result: Not running on Whonix-Gateway., ok. [WARNING] [whonixcheck] Tor SocksPort Reachability Test Result: Unreachable! (curl exit code: 28 | curl status message:  - [Operation timeout. The specified time-out period was reached according to the conditions.]) [ERROR] [whonixcheck] Tor Connection Result: Tor's Control Port could not be reached!
Did I miss something concerning time-out periods? I have no idea where to change this – and never had to do/change something like this.
Thanks a lot for any hint,