Meanwhile,
check the power connector to the SM7 and try a different battery. Reduce the volume, does that make any difference? Does it also happen without using the horn?
I appreciate your help Jörg.
The SM7 works fine on 2S lipo connected at the M24 and K40. I will try to connect a 3s lipo on those to verify if the higher voltage could be the cause of the problem on the SM7.
The reset happens every time after the motor startup. On the video it happened on both the 2 times I started the motor sound. The horn sound does not influence it.
I used the T24 with the SM3 on 3S lipo since I made the video and it is working fine.