@bottojr, I have been suffering from this issue on multiple machines for two months.

Have you tried uninstalling the most recent Windows update, e.g. 2020 May Cumulative Update. I uninstalled the most recent update using DISM.exe (see here) and I got the XPS Document Writer back and fixed QuickBooks saving. You might also need to uninstall April updates.

Do you see the XPS Document Writer listed when you run get-printer in PowerShell?

You can also try disabling and re-enabling the XPS writer optional feature. You can do this in GUI or PowerShell:

Disable-WindowsOptionalFeature -Online -FeatureName "Printing-XPSServices-Features"

then

Enable-WindowsOptionalFeature -Online -FeatureName "Printing-XPSServices-Features"

Could you also tell me if you are using third-party AV and what your QuickBooks version is?