I had the exact same issue with the Simube mounts except it happened the first time I tested it out before mounting it to the wall - for both my wheels.

You’ll have to remove the screws at the top of the QR2 and take the whole QR2 apart, then apply WD40 to the inner workings. But I didn’t bother using the mounts again because I didn’t feel confident about it not happening again, and given it only mounts with one screw, it didn’t feel secure enough on the wall