Just for clarity, this is the VZM35-SN and you’re using Z2M to control a ceiling fan (not fireplace fan as in OP)? Did it work fine with ZHA and it’s just with Z2M that you’re running into issues?
I’m not very familiar with the config in Z2M unfortunately, but you might want to try a separate post just to keep the details clear if someone with more knowledge there can take a look?