The unity version I use is 2021.2.0f1.
I have a ScriptableObject script with enum field. In the CustomEditor of the script, I use PropertyField to create for enum field. If the enum value is changed in the Inspector, an error will be reported, but if I replace the PropertyField with EnumField, there will be no problem.
Each field in enum adds an InspectorNameAttribute. Of course, if the InspectorNameAttribute is not added, there will be no problem, whether I use PropertyField or EnumField.
I knew what unity going to say: submit bug report.
Support for InspectorNameAttribute and most other attributes will be coming in 2022.x
But afterall, @eggsamurai is right!
For the issue regarding PropertyFields and enums, can you file a ticket with Help-> Report a bug ? If you can provide a copy of your editor script that will sure make the fix easier. It will also help us track the issue and help backporting any fixes once they land into the latest version.