Corrupted form fields?

I am working on a legacy (ca. 2016) PDF and attempting to tag and make it accessible. This PDF has a number of form fields, some of which have multiple annotations. The attached image shows a text field that has three duplicate annotations (two of which are highlighted on the right side, in the Fields list).

I am unable to delete these duplicate annotations. I have also tried to delete the text field directly, but this leaves a weird "Field" reference that I cannot delete either.

Has anyone expereinced this behavior before? Any suggestions on how to clean this up? It really does seem like these form fields have become corrupted, and other than starting over from scratch, I am at a loss as to how I should proceed.