Throwing a P0770 code after transmission rebuild

[OpenYota]

2001 4x4 automatic 142k miles

My transmission went back in April and I had it rebuilt by a reputable shop and everything seems fine. Scanned the car today with my OBD tool and saw I was throwing a P0770 code.
I’m going to try and clear the code again and see if it comes back.
I don’t notice any issues while driving or shifting, do you guys have any suggestions what could be the issue or what the proper steps of curing this code are?

 

[jgue467]

Mine threw same code about 5-6 years ago, once, cleared it, never again, no symptoms either. I consider it a 'fluke' after all these years of not repeating, so the system apparently can make a 'mistake'.

If it comes back after clearing, I assume the shop has some kind of warranty/guarantee?