This is a known issue. It appears to be specific to fan installations. There is a beta software version (1.0.1) that appears to fix the problem.
It has been discussed here:
https://community.inovelli.com/t/white-series-on-off-bug-enhancement-vtm30-sn/20213/51
I believe that there is now beta version 1.0.2, though I have not seen any release notes for it.