As I look at what is happening, it looks like the default route was somehow not working anymore, as any other route still worked.
After I restored the harddisk (not VM hardware) everything works again, so it looks like a problem with corruption or configuration of OpnSense on the harddisk.The fact that restoring the Harddisk only solves the problem, rules the VM environment out (for me that is).
Do you mean restore the virtual disk that the virtual machine is using? and are you using zfs or ufs as the filesystem?kup. Sorry but you haven't ruled anything yet in terms of environment.