Clone Commando Gregor (CC-5576-39) was shown in Star Wars: The Bad Batch Season One episode 14, "War-Mantle":
Post Order 66 and the rise of the Empire, Gregor had attempted to escape his role as a trainer of the new TK Storm Troopers at the training facility on Daro, when the Bad Batch were sent in to rescue him by Rex.
This suggests that he was not under the influence of the inhibitor chip at this point, due to not demonstrating the blind obedience of the other regular clone troopers.
While it is confirmed in Star Wars: Rebels the Gregor's chip had been removed, there's no details given as to when.
I didn't betray my Jedi. Wolffe, Gregor and I all removed our control chips.
-- Commander Rex, Star Wars: Rebels S2E02 "The Lost Commanders"
My question is, when was Gregor's chip removed?
If it was removed before he went to Daro, why did he go there in the first place and not defect like the Bad Batch and Rex already had. And if it was still in place and functioning, why would he have attempted to escape?
One minor factor that may have affected this reasoning is that when first encountered, in Star Wars: The Clone Wars S5E12 "Missing In Action" he is working in a cantina having lost his memory, presumably as a consequence of a head injury sustained during the Battle of Sarrish. This same head injury could possibly have damaged the inhibitor chip, which would add a third possibility to the circumstances in The Bad Batch.