I have had problems with the Flashpoint R2T (Godox X-1T) Transmitter being too close to the StreakLight 360 TTL (Godox AD360 II) or my receivers for consistent triggering and noticed that this has been a problem for other photographers as well.
Here is a solution that was provided by a member of another forum who is very proficient with the Godox type flash system. I thought that I might share this solution with other photographers...
Richard, have you tried putting the X1T into "close" mode? This was added in a firmware update after initial release because of issues with triggering when the flash/trigger were close together (within 1m). On the X1T-C, you have to be at firmware v15 or later (you can check by holding down the MODE button while turning on the X1T), and you turn close mode on by holding down the TEST button while turning on the X1T. The STATUS light will blink for 2 seconds to indicate "close mode" is active. You will have to do this every time you turn the X1T on, btw. However, on the XPro, the "DIST" C.Fn setting will stick between power cycles.
I didn't even know that there was a firmware update for the X1T
This is, in fact, the board where I learned most of my Godox knowledge and folklore. Mostly from the venerable 90+ page 
