I don't know, then. It's unlikely to be a hardware problem with your seppuku unit because if something was going wrong with s.bus, etc, it would detect failsafe. The flight controller isn't resetting and is keeping running, but it is acting as if it has received a command to disarm (or a disarm timer has expired).
No other reports of this problem / and it doesn't occur on my rigs with XM+. Sorry-- please let me know if you figure anything out.