If I had to guess, I would guess that the switches are confused and think they’re waiting for an over the air firmware update which is never going to come.
This would be because of a recent change to how SmartThings handles zigbee. The hub now broadcasts a message that it is capable of doing over the air firmware updates, even though it will only do them for a couple of SmartThings-branded devices.
This message in and of itself is causing some of the others zigbee devices on the network to start doing strange things.
Definitely report it to support.
You can read about the issues in the following thread: