dynamic network attach/detach does not work (kernel oops) · Issue #975 · QubesOS/qubes-issues · GitHub says this now should be fixed. Please update your TemplateVMs. And update dom0. Updating from Qubes stable repository is sufficient.
Should this then still not work please put this upstream to dynamic network attach/detach does not work (kernel oops) · Issue #975 · QubesOS/qubes-issues · GitHub.