Hi @AntonJansen ,
Regarding tip 1. I tested a rule that sends the “reverse” command in a loop for 4 times with a 500 milliseconds pause between each command send. Unfortunately, that didn’t solve the problem. I can see the RM4 Pro LED turn on when it’s sending the codes, but the command aren’t received by the fan.
Regarding tip 2. Like I wrote yesterday, I don’t think these fans have changing RF command codes, because when I configured OpenHAB (prior to version 4.1.2) with the old Broadlink binding, I was able to properly send the reverse codes, without the need to send them in a loop or in another special method.