Not sure why that’s happening on your end. For me it works without any additional code:
I forgot to mention it before, but I will stress that the property drawer has the potential to not work properly on any version before 2022.2.12f1 or 2023.2.0b15, being the version where IDisposable
support was added for property drawers (Thank you for doing that Unity). Not sure what other Unity versions are getting that addition.
Versions before this could potentially run issues due to not being cleaned up correctly.