When you start typing in a single or multiple select field, a drop-down appears that shows matching options, or allows you to enter a new option.
Obviously this is super useful–the problem is, the behavior of the “enter” key is ambiguous in this context. In the attached screenshot, you can see that if I want to select “ASAP” here, all I need to do is type “as” and press enter or tab. But sometimes this instead adds a new option named “as.” This happens to me almost constantly, and it’s… kind of infuriating. I have to fix the record itself, then go into “customize field type” to delete the “as” option.
I’m guessing what’s happening is that “create a new option” is loading more quickly than the match results do? In which case maybe just making sure it doesn’t appear until all potential matches have been checked might solve the problem. But another option that might have additional benefits would be to lock the options so that you can’t add a new option without going into the “customize field type” menu.