[magnets]

The failed bearing on the left confuses me.

My experience with hex bearings is that they are hit or miss in terms of quality from all vendors. None of them roll as smoothly as the comparable round bearings, and they have varying degrees of accuracy with runout and hex sizing.

Generally, I'd try to avoid them if it all possible. Even if you think they're strong enough, dealing with availability and variation between suppliers can be frustrating.