Seamaster Power Reserve Issues Despite Multiple Servicings

I have a mid-2000s Seamaster (Calibre 1120) that has a persistent power reserve or winding mechanism issue. I fully wind it manually every six days then wear it daily. Frequently, it will stop overnight on the fifth or sixth night with the hands showing that it ran for 8-10 hours after I put it on the nightstand.

Certainly, I could manual-wind it more often. However, I don't recall EVER having to wind the watch manually when it was new or before my most recent full service in 2019. Since then, I have sent it back to Omega/Swatch service centers multiple times with a full description of its behavior. Each time, the watch is returned with a note saying that it has been returned to full factory specifications. Nevertheless, I'm still experiencing the same behavior.

So, my questions for the group: Is it normal that a watch of this age needs to be wound manually so frequently? (Are my expectations out of line?) If this is not normal behavior, how to I persuade Omega to address the problem? (No matter what I say, it seems to trigger a routine maintenance service that has no effect.) Should I seek repair/service elsewhere?

The only bright spot in all this is that all subsequent services have been at no cost to me under the service warranty.

I'm also curious about this. How do you know when an auto movement is fully wound? 100 turns of the crown?
My apologies if ive derailed the thread.