Just went through something similar on Ubuntu 20.04. Make sure you have the latest tested drivers installed through the ubuntu software updater. Make sure your steam library is on an ext4 partition. Delete all files within the steam compatdata folder. Delete proton 5.13 and steam linux runtime soldier. Within the steam library do a search for proton 5.13 and steam linux runtime soldier. From there you can verify the tool integrity. This fixed my proton 5.13 issue
I'd suggest destroying the vagrant VM and letting it try again. Run vagrant destroy in your proton directory, then try make install again.
proton 5.13x2 2020-12
Hardware: https://linux-hardware.org/?probe=d802289f2c
Ubuntu 20.10
FontForge is installed, trying to call it manually opens it
Any ideas?