Since around Home Assistant version 0.71 the issue seems the be resolved for me. I’ve upgraded three time since and the problem did not return anymore. Not sure if it is related, but I’m keeping my fingers crossed!
UPDATE: I’ve manually updated to HassOS when I’ve done the update to Hassio 0.74.2. Since then I’m seeing this problem again after 2 or 3 days collecting data (without updating). I’ve rolled back to ResinOS now.