OK, when it first came out, that device had a known SmartThings issue where the physical switch was sending a code that was 8 digits long but ST was only processing the first 4 digits, which meant that an On was ignored. However, if it’s properly wired it should still have controlled the load at the switch unless you’ve set it up just to be wireless.
This is now an officially supported device, so the first thing I would do is contact support. You might also point them to that forum link so they can check and make sure that’s been fixed in the official device type. I assume it has, but it never hurts to check.