Cannot edit text box in Photos

I'm trying to edit text boxes made in Photos using MarkUp. I can do this immediately after creating a text box, but if I wait and go back to it later then I cannot edit it. When I return to MarkUp mode and click on the text box nothing happens, I just see a small icon that is possibly a paperclip (??) and the box seems to be "locked." I've searched by subject, and have also tried to find an explanation for the paper clip looking icon I see.

I can't edit on either my MacBook or my iPad, but I only see the unknown icon on my iPad.

I assume I've done something to "lock" the text box, but I have searched and tried everything I can think of to fix it, but have been unsuccessful. Please help if you can. Thank you!

MacBook Pro M1 (2020) running Monterey 12.5.1