Relay Switch Fibaro erratic behaviour

situation:
I have a Fibaro double relay switch (fgs-222) that I use to control my bathroom ventilation. Three possibles modes: off, low, high.
Frequently (with no obvious pattern) the switch reports back that it is in one of the three states (e.g. off when i needs to be off) while in reality the device is in another state (reports: high, while turned off; or reports low while in high. etc)
partial remedies:

  1. sometimes the issues resolves by itself af an hour or so
  2. in case i need to take control i have the restart homey (restarting the app doesnt suffice), and even then succes is only guaranteed in approx 75% of the cases

question:

  1. how to proceed with troubleshooting in order to determine the possible causes of this problem
  2. (and if there’s anyone out there with a similar problem, and fixed it, that would be even better, but found nothing on the forum