I saw this question posted from a few years back, and it sounded like the issue was being resolved, but I'm having this issue described back then.
I have a set of repeat questions, and am using an expression (using an Index calculation and a max(index) calculation to verify if it's the last record. Anything except the last record is set to read only to prevent editing after moving to the next record. The field in question has a combination spinner/numbers appearance. The expression removes the spinner appearance, but not the numbers appearance, and it is not read-only.
This seems to be restricted to the combination of the numbers appearance/read only expression, as if I remove the numbers appearance, it works as intended. If I only have it set to the numbers appearance, it does not work. It works fine if I have it set to only the spinner.