Problem with one of my two tentacles sending signal to Arri Amira

Shooting with two Arri Amiras yesterday and jammed both A and B cam Tentacles with sound man.

Signal from A cam Tentacle wasn’t being read by the Amira.

Switched A cam to B cam Tentacle and Amira reads TC.

Switched A cam Tentacle to B cam cable no TC.

Switched B cam Tentacle to A cam Tentacle cable Amira reads TC.

Put B cam Tentacle in jam mode and jammed with A Cam Tentacle (Tentacle to Tentacle cable. B cam tentacle accepted jam.

Repeted process with B Cam. B cam jams with B Tentacle but not with A Tentacle just like A cam.

Tested both jam cables with both cameras only B cam Tentacle jams both cameras. A cam Tentacle does not jam either camera but jams B Tentacle. Checked both Tentacles with phone app OTG, settings are the same.

My theory is the A cam Tentacle is malfunctioning. Am I missing something? And if true how do I start the repair process?

edited question