The smaller arm has an issue every so often with the enclosures for motors triggering (it’s usually the encoder for motor #1 or #2 floating). The cable connecting the arm to the controller eventually needs to be rebuilt, but for now it should be holding. If you open the hardware diagnostics and see the position value fluctuating wildly then it’s the floating encoder. This also sometimes happens when one takes off the back panel; the logic board attached on the back panel has a lot of PCB connectors that do not have locking tabs. There is a two wire green PCB connector in the lower right quadrant (facing the board) that tends to come loose most readily. IIRC it’s labeled “Y22 / Y21.”
If that’s not it and it’s the big cable, sometimes propping it up with the wooden block just before it connects to the arm solves the issue (loose pins) without taking it apart. Last time I moved the arm I didn’t need the wood, but I didn’t make it out yesterday to the meetup and see for myself what’s going on.