@pablo11 I think you’re gonna love this one. You’re finally going to find out what happened to my APPLLP and it probably would not have if I had read the whole Android 11 is here! Lokmat APPLLP 4 Pro and LEM16 Z40 models thread before. I’ve seen your comment with a picture of dev board there so if there is nothing that can be done, I suppose you can at least appreciate some humor at my expense 
I am going to post a new topic for this since the abovementioned one already has 200+ pages, plus it’s not as a general issue as that thread is.
So APPLLP was my first watch with this magnetic 4-pin pogo USB connector, I also got for my wife a Zeblaze GTR3 which came with a 5-pin connector, and since I wanted a spare cable for the office, I ordered one more 4-pin cable which came with the magnets (and pins) mirrored, so the cable was pointing out on the other side. With all these cables now, some seemingly compatible and some not, and all connectors and pins so exposed, I was curious if the watch has any kind of protection against using the wrong kind of cable.
Referring to your comment just a little below the previous one, which I read just a few minutes ago, where you warn about using certain cables with different polarity, I think you must already expect which way this is going 
As they say curiosity killed the cat, well, in this case it killed my watch.
I even forcibly connected the 4-pin connector the opposite way and now every time I connect power, charging status shows up and immediately goes away, then this repeats forever, even after I remove the cable, until the device is restarted. From here I think a bit of the story is known from another thread, where I bought a cheaper replacement, then out of dissapointment ordered LEM16, and only then found out that APPLLP actually still charges, I’m just not sure now if I need to turn it off before (seems to work better) or does it still charge if it’s “on and blinking”. Usually the off-state-battery-indicator updates the state while it’s charging, though just today I have noticed that while it still showed about 20% from last night, when I turned it on it was at 100%. Could also be that while it’s charging in the on-state it cometimes can’t read or update the current power level? Just brainstorming while describing the symptoms. Sometimes I have to power-cycle the watch a few times before it starts charging seemingly without issues, but even that I am not sure if because I am doing it or would it also be okay if I just left it alone for long enough the first time already.
Anyway I’ve tried having it repaired, but there was nothing they could do about it. Do you know any better from the top of your head? From just that single picture I assume that you at least have more experience and knowledge about it than them. I was thinking, maybe the power unit can be used from some other compatible device if they have the same specs. Though, frankly, considering everything above, maybe I better not think too much
As an added bonus, all this was AFTER finding out that you can’t charge the power bank via pogo pins side neither 
In the worst case I will now apparently have two of the same working watches with one just needing to be off while charging (or reset after) and the other one, which I will hopefully take better care for. And another one which I will most likely never use again anyway and already by its name “H08” - or “H - zero (which can be left out) - eight” proves the nomen-est-omen regarding my feelings towards it (I hate it).