Internal wiring looks good.
Wiggled ppm wires and can wires at both ends and in between while running. No cutouts. All connectors are held in with hot glue.
Disconnected receiver while running. Primary motor stopped after 1s. Secondary stopped 1s later. On reconnect it starts up again.
Disconnected can bus while running. secondary motor stops after 1s. Reconnect and it starts.
Disconnected ble module (it’s on primary) while running. Motors run per normal. Xmatic disconnects. on reconnect of module xmatic reconnects.