5.3.8 had a bug, was this a radio field? It was reported here https://support.advancedcustomfields.com/forums/topic/choice-field-other-repeater-issue/
5.3.8.1 was supposed to have fixed it. At a guess, the renaming happened after updating to 5.3.8 and then the field was left with the wrong name when you updated to 5.3.8.1.
If this is not the case, please post more details about the types of field that’s being effected and how it can be recreated.
