Create a Java action to do that for you.
The Java code is really simple:
return Core.retrieveId(getContext(), Core.createMendixIdentifier(guidParm));
Yes, I stumbled on this as well. I ended up saving the GUID on the object and using that in my selections.
It's really strange that this is not working (or no longer). You can always add another attribute and use the comm.commons getGUID action to set it.
I suggest upvoting this idea
and else, there's always java
retrieve from database
using a hardcoded string
[id = ‘1234567’]
or using a variable
[id = $Variable]