I have several Fibaro FGD-211 and FGD-212 on Smartthings Hub 2 with Momentary Switches (MK Grid type).
When I initially add a dimmer to the hub it works fine on both the wall momentary switch and also with the app and Z-wave control via the hub. But after a few minutes, the hub seems to reconfigure the dimmer parameters(?) so that the wall hardware switch doesn’t work at all. The app continues to work fine for control. I note that there are some Device Handlers in the smarttthings community that should solve this problem but don’t seem to.
This is quite a critical problem as I have dimmers in every room and at the moment I cannot connect them to the hub - otherwise when you walk into the room and use the light switch it doesn’t work.
(also posted on Fibaro forum)