I also would only use Xantech emitters (The Crestron ones are Xantech...)
I have used every other major brand of emitters over 36 years and had issues with all of them (with/without Crestron) and the fix was always to swap them out for Xantech!!
There is NO good reason that Xantech LEDs are that much different from all others but apparently they are!??
I refuse to Trouble-shoot IR issues until the polarity is checked and emitters are swapped to xantech...
(I wish I owned stock in them!? HaHa)
