So i was hunting for a new watch on craigslist. I seen a guy that was selling a brand new Gear S2. I completed the transaction however before that i called both carriers. T-Mobile Stated to me that it would be no problem changing over the watch to the T-Mobile network as long as the watch is unlocked. I called AT&T and they stated that as long as the watch is not under contract still, unlocking the watch is no issue. So i got the IMEI number from the seller and checked it with AT&T and it was indeed not on contract. So they sent me the unlock details but turns out after i followed the process it appeared that the watch was already unlocked. So i called T-Mobile; and it was a nightmare getting my account re-worked for wearable's but once that was completed they asked for my CCID(sim number) by dialing *#06#. when i gave it to them they stated that the CCID was 20 digits and it should be 19. After a few phone calls to T-Mobile and troubleshooting sessions i was finally told that the system doesn't support 20 digit sim card numbers which is why it pulled up with nothing when it was checked.
Now i did some research and apparently Samsung implemented E-Sims into these new watches in order to ensure interchangeability between carrier networks so i am not sure what to think here. I am looking for help to understand what the limitation is. Is it actually the T-Mobile network that does not allow 20 digit SIM's or is it something that im doing wrong in getting the correct number.