On List libraries that have a Choice field, with the "Allow 'Fill-In Choices" option enabled; after you make a selection and click on a different field:
a) The selection you make is cleared and the field reverts to being empty. b) The list gets a new empty entry at the bottom of the list.
If I disable "Allow 'Fill-In Choices" on the field and then re enable it, all my previously filled in choices are erased, the erroneous empty values are erased, and the problem returns.
This is happening on two different SharePoint Online sites, and across multiple list libraries. The feature was working previously (prior to the time of this posting), and seems to have only appeared this week (or even today).
What would normally be the cause of this problem?