I've been running 86Box on both PopOS and Kubuntu for months with no issues, so it could have something to do with Linux Mint specifically.
I noticed on their 22.3 release notes, they note that 22.3 ships with Kernel 6.14 which does have issues with Virtualbox. While that's not 86Box, perhaps it's a shared virtualisation/emulation issue.
For reference, on Kubuntu, I'm currently running Kernel 6.8.0-90 which has no issues with 86Box or Virtualbox.
They do say in their release notes that if you're affected by issues, try installing Mint 22.1 which ships with the 6.8 Kernel. Perhaps that could solve your problem?