Disappearing pix & vids

I don’t know what it is but I’m getting several weird things happening with my Mac Mini (Sequoia 15.7.6).

File sharing has gone haywire. None of the shared folders and drives are visible to anyone. Sometimes after a restart they are, but most of the time they are not.

The thing that is nagging me now is that images & videos received via Messages (of which I get a lot with having two very photogenic granddaughters) vanish without a trace.

Normally. hitting the little download symbol next the pix transfers them straight to Photos.

the green tick appears but nothing arrives in photos.

I I go back to Messages and right click a pic, there is an option to ‘download to Photos’.

If I select that I get the message that this image is already in Photos, do I want to save a duplicate?

I I say yes It indicates that it is saving. but where? I can’t find it.

If I use Find duplicates in Photos, nothing shows up.

I’m now completely baffled, I just dragged one of the latest batch of offending videos directly onto Photos from the massage and it imported without a problem AND without saying this video already exists .

I think I’m going to go for a lie down.

It might be worth updating to 15.7.7 just to see if that cleans up preference corruption or the like.