I have a support ticket (#02569292) in for this and Esri cannot duplicate it. I am surprised others are not posting on it because we have this happening in multiple Enterprise geodatabases where a split of a polygon creates a null geometry record. Sometimes you cannot get rid of the record. I've also been able to replicate this in multiple hosted polygon layers agol (editing them in Pro). A video of this on a agol hosted layer included, and an image from an enterprise based polygon layer too.
If anyone has any ideas, we'd like to hear them - we're stumped!
btw, this is not on every split done in Pro. it's intermittent.
Can you examine the data to see if this is possibly occurring with polygon contain true curves? If you cannot determine this, then try copying the data, planarize the copied data (remove curves) and try the same split operation to see if you get the same results.
I am OP, on my own account now. I think we have true curves on one enterprise layer where this occurs; I am pretty sure we need this feature. Several hosted layers don't have this metadata on the rest endpoint so hard to tell.
I am just saying to run through this workflow to determine if true curves are the root cause so you have a better chance of ESRI duplicating the issue, if that is even the issue.
Could it have anything to do with feature visibility based on a an attribute being used from a domain that gets set to a null value during a split based on default rules? There are other threads that talk about that issue so I would do a keyword search on the forum to look for those threads which might help identify your issue.