EOS M5 and external flash test firing

Has anyone else experienced problems with firing a test flash with an external Speedlite attached to a switched-on EOS M5? I've tried with: 430EX II, 600EX-RT and a Aodelan E3+ transmitter. What I have found is test flash always works with the body switched off, but when on...

• It never fires from the transmitter.
  
• With Speedlites it works sometimes. I can't figure out the pattern.
  

ettlz wrote in post #18770966
Has anyone else experienced problems with firing a test flash with an external Speedlite attached to a switched-on EOS M5? I've tried with: 430EX II, 600EX-RT and a Aodelan E3+ transmitter. What I have found is test flash always works with the body switched off, but when on...

• It never fires from the transmitter.
  
• With Speedlites it works sometimes. I can't figure out the pattern.
  

Note that the flashes all work OK when actually taking a shot or using the modelling light. All flash kit works fine on my EOS 50D and 7D bodies.

Can't answer for all your gear.

But my M5 works properly using the Phottix Odin units on Canon 430EX ii and Flashpoint 360. If I recall, I needed to do a firmware update. After I bought the M5. one of the receivers worked, and the other 3 I connected for the firmware update.