Win10 VM unresponsive to RDC after a while

Has anyone come across an issue where it becomes impossible to connect to VM through using remote desktop connection after it's been running for a while?

This is a Win10Pro Guest with spice/QEMU.

Using console does let me get into the guest and then occasionally then remote will work, but sometimes even the console doesn't respond and is stuck on black screen.

I've got plenty of resources available on the server, so can't imagine that being an issue, unless there is a memory fault.