Same findings. Fully changed battery. I suspect they have a very low powered reader (to conserve battery) with weak signal/short range.
Regarding the bytes from the fob I got with the lock: In my case it uses 2 bytes (that’s 4 hex digits, so I suspect that’s what you mean) and when scanning the fob with my phone, those correspond to the second and third byte of the fob’s ID.
I wonder however if putting in the 2 bytes in the app is enough. It’s possible that those 2 bytes map to a full length ID in eGeeTouch’s server side database, and you’re expected to by extra fobs from the manufacturer. I doubt it, but it’s possible. (You can order additional eGeeTouch fobs on amazon.) The manual is… brief.
What puzzles me right now is that I tried registering the second+third UID key from an ordinary NFC plastic card, and the lock wouldn’t work with it. Either 1) It’s not as simple as registering second+third UID bytes, or 2) the signal is weak enough even for a non-implant regular plastic card fob.
I note that the fob I got with the lock is a Mifare Ultralight. Does this matter? How much does this increase the probability that a Mifare Classic/xNT (not being Ultralight) is never going to work?
I’ll post more info when I’ve done some more testing. My next step is to try registering more fobs.