battery discharges fast

I upgraded to 15.71 Beta and the battery resolved. Try to do that.

Just got my 6s pro watch a week ago and updated to 15.20 the second day I got it. I am having roughly 1% drain per hour without activities, with no bluetooth, no wifi, no pulse OX, just regular HR measurements, with stock watch face (no seconds and no weather). My gesture is turned to after sunset, 20%, 4 seconds. I've tried hard reset twice that deleted my activities, tried the plug into computer and hold light button restart + charge 1 hour past 100%. Anybody else have similar issue with these settings? It seems once I connect to my phone then shut off the bluetooth, it just consumes 1%/hour. That is pretty terrible for no connection to my phone while on plain watch mode.

Yeah, same here. I am pretty shocked,coming from an Instinct SOlar, I got the Fenix 6 X Pro because it was supposed to get pretty good mileage, but mine consumes at a rate of over 30% a day.

My 6x has been getting gradually worse with time, and recently (post install of 16.0 beta) started losing about 20%/day in standby.

I deleted the garmindevice.xml file & saw a brief improvement then back to 20%/day;  factory reset via the menu (not much difference); finally a bit over a week ago factory reset via the three-finger salute then installed beta 6.10, which saw the performance go back to as-new, around 6%/day in standby with Bluetooth active to the phone.

I had a talkytoaster map which I've now reinstalled, which has not affected the standby at all but is possibly affecting the battery life in activities where it's heavily used.

I was using ConnectIQ fields for Stryd power, a race screen, and gimporter for wireless transfer of route files. I haven't reinstalled those as yet but will do that in stages and report back (by editing this post if possible).