How to fix FreeBSD (Opnsense) freezing on KVM?

Question

linux

There is a small virtual machine on Opnsense (the version does not play a role, we tried it on different ones - there is one problem everywhere). 8 processor cores and the same amount of RAM. Virtio drivers are used everywhere. A virtual machine running KVM on Debian 8.6 is running.
The crux of the matter is that when you turn on the virtual machine, it freezes during loading, just at the moment indicated in the image.
Hangs tightly, only destroy and restart helps. After the restart, it turns on and works stably, without freezing. I suspect. that the problem lies in USB devices, but I would like to hear the opinion of those. who has experienced this.
Alternatively, is it possible to simply remove USB devices from the virtual machine config, will there be any problems after that?