"poll groupable user fields" setting doesn't find existing user fields, have to enter them manually

I’ve created and filled in two user fields.

The poll groupable user fields setting placeholder says “Search or create”, but it never finds the existing user fields. I have to write them entirely, save, and then they will work in polls.

The expected behavior is that it should find the existing user fields, and allow selecting them instead of writing them from the first to the last letter.