I liked the Siemems load centers, but with the ones just installed, both had problems with the main breaker. The cap bolt on the main breaker was loose on one and the other panel, Main breaker would not go to off position. Sent them both back.
These problems started about April or May of this year. Could be they were made on a Monday or Friday. You are right, I never had those problems with CH Panel. The loose cap nut, I can understand it being an assembly error. But the breaker problem is what concerned me. I think it may be the way it was shipped caused the problem, the box was beat up with holes and rips on the sides. My fault for accepting it.