I'm using ArcPro 3.4.0, and every time I edit an annotated label, it snaps back to its original form. I tried using the Upgrade Dataset solution suggested in Problem: Unable to Edit Annotation Features in ArcGIS Pro but it gave the error "The dataset is already upgraded."
Question for you - are you using a file geodatabase or an enterprise geodatabase. If eGDB, is the feature class versioned or non-versioned?
@ThomasGoodridge Try making a copy of the annotation and see if the edits stick on the copy.
Another option is create the annotation layer again. Delete all records out of the layer. Then copy and paste the original edited annotation you're having trouble with into it, and see if the edits stick with this version.
Jon