Omega Seamaster Apnea 2595.50 Caliber 3601, low power reserve and inconsistent accuracy, does it need service?

Dear forum members,

I own a Seamaster Apnea (2595.50.00) with the caliber 3601 which has an ETA 2892-A2 base with a Dubois Depraz 2029 Chronograph module (to the best of my knowledge and the limited info available).
Lately the watch started to lose 1 minute per day while having a power reserve of 2-6 hours (from being manually fully wound). When the watch has stoped, I though to activate the chronograph. Turns out that the when the chronograph runs, the watch is accurate from -5 to 0…

Read more