Just a quick update on this. We had a call with MS Support on this today and in between I had added a variable at the top of the code for the form that was causing the issue:
Dim Test as string
I then saved the workbook and re-opened it and the issue went away.
It also went away for all other users that had been updated to v2212 prior to me saving the workbook. However, one of my users auto-updated to v2212 today and the issue came back for her...
MS Support also gave me a registry setting to try as well. See below:
Reg.exe add "HKCU\Software\Microsoft\Office\16.0\Excel\Options" /v "ForceVBALoadFromSource" /t REG_DWORD /d "1" /f
You may want to try this with users that are having the Compile Error issue where you get a Variable not defined error.
I haven't tried the above solution yet so I cannot confirm if it worked or not. Just passing on the info from MS Support.