Ah, a bug. Great.
There's several hours of my life I'd like to have back. Shouldn't they at least buy us a hat or something?
Thank you for the info.
Does your look up fail in the pattern reported in the issue report?
I've long seen look ups fail when one field auto-enters data that is then used as the match field to look up related data. This, different issue, seems to happen because the second look up is attempted before the data is entered by the first. I've sometimes used a script with a script trigger to work around that particular timing issue.
It seems to fit.
There are three fields auto-populated when you create the record (Creator, Modifier, CreatedFor - the last one can be changed) and only Modifier consistently works across all access levels. The "bread" of the sandwich of the three fields is what fails, but it works if you enter the field and exit it again. It's one of those "I've been riding a bicycle for so long, did I forget how to ride a tricycle over
I could change CreatorUUID to a calculation instead of a lookup and see if that makes a difference to the other one, but the others have to remain lookups.
I don't see how that fits the pattern of the bug reported in that other thread. It sounds more like the issue that I have seen where FileMaker appears to try to look up data in one field before the needed data in another field is auto-entered and thus fails to link to a related record from which to look up or auto-enter the needed data.