I had similar issues on a long run (with 3x 4-ways in it, and maybe 160ft of line between the switch and the furthest fixture). It always displayed that it was on, and down toggled the actual light status. Up did nothing. In my case one orientation if the dumb switches made things work better than the other.
I didn’t get anywhere with Inovelli on it, and eventually shortened the load by removing the last 2 switches and half of the fixtures, and now it works consistently (the last 2 were motion fixtures on the garage, so they’re fine to be hard powered)
I always assumed that it was an issue with the current detection in the dumb switch mode when there’s enough wire and fixtures on the line, it always detects the lights as on, probably due to the capacitive load of the wire.