Sync does not put all photos back on iphone

This has been going on a long time. I don't sync photos to cloud because I have 34,000 and I'm often where there is poor service of any kind.

I have always backed up my photos to my mac. This issue of the sync just putting random photos has been going on for year. I used to be able to have the finder not sync photos to the phone (13 Max 15.3.1) rebuild the index on the mac and then resync. About 2 times a year it would start the random only sync some things back. Now under 12.2.1 I tried to have it erase the phones pictures. It says it's synced with nothing to be moved and to remove all photos but... the same photo's are still there. I rebuilt the index no problem, it says it syncing my 34K pictures on the finder window but...when it's done, only 24,000 on the phone. Just did it again and now there are only 10K. I must be the only person on the planet that has had his issue as I can find no support on this. Suggestions?