Mine are staying delete now after initially a few popping back up.
Something like this happened for me too, but I believe these were comments that I didn’t yet delete, they just weren’t visible anymore. The older ones started to pop up once there was new space for them after deleting the newer ones. (On your profile not all comments you ever made are visible, only the newest/top/most-controversial ones, depending on what you sort for).
For example in my profile my very first post was visible, but none of the comments I made there. Before deleting the posts I went through each one and deleted my comments that way. There probably still are many comments from me laying around undeleted…