I've had almost every generation of Apple Watch, and the Ultra is yet another that has the same issue - so no, this has decidedly not been fixed if you're holding out for an answer. I have wrist/hand tattoos (full color) on both sides, and occasionally I can get it to stay unlocked if I position things just right - but the moment I move, instant lock. It seems to be less sensitive if I have an active workout running, but that's not certain - and it's really frustrating that once it locks, it pauses that workout and I lose that data. What's mystifying is that it's showing heart rate the second before it locks, so it doesn't seem as though it's a sensor freaking out. (and indeed sometimes when I'm on completely bare skin I see the heart rate greyed out at other times - so it's not a correlation/causation thing)
Solutions I've tried:
The bottle cap trick: it works mostly but is a pain and I feel it affects the speed/consistency of charging. It still locks, just not as often. It also makes the watch "taller" on my wrist
Disabling auto-lock: the watch is basically useless in this mode, so not even really an option.
Repositioning/loosening bands/different bands: no real consistent effect here. Might get lucky now and then but the only thing consistent is the inconsistency
The only thing that works: wearing it upside-down on one of the few places under my wrist where I have bare skin: works, but I'm constantly bashing the face on things and that's not ideal either. It also sort of messes with the auto-wake/positioning sensing. I've lived with it this way, though.
What I'd love to see is an option in the settings much like the OSX screensaver settings that sets a timeout for auto-lock. I feel like if we could just say "don't auto-lock within {x} second(s)" or something that the watch would once again find the consistent skin that it's looking for - because when it locks, it's instant. Or maybe being able to pair the lock status with a phone in the opposite direction? (much like how the watch can unlock the phone, why can't it work in reverse?) I don't know, I'm not an engineer and I'm sure someone at a billion-ty dollar company has already thought of all of this and surely someone in that place must be tattooed.
Yes, I'm sure there are people out there laughing and saying "wElL tHis iS wHat yOu gEt for bEiNg taTtooed" - save it, I don't care about your opinion. This is me and it's what I like - it's irrelevant to the issue. I'm just stating my experience so others can make a decision based on that.
