Use a timer it's the only way to fully cut power to it when it's off. I have a TSW 2000 and mine flashes on/off when the switch is off if I don't use timer, fkd one of my crops.
I believe the problem is the switch and not the drivers in my case, redardless...crappiest company to buy a light from imo. Bad customer rep...will try to get you to improve ratings in exchange for warranty service. Better niche market for them would be in the garbage disposal business imo

Those Kasa Smart plugs work great for setting up schedules for on and off times and cutting power (They are pretty cheap too). I've heard the same thing about the lights not fully shutting down 100% with Mars and other models for that fact too.

IIRC I saw a response from Mars support on Reddit where they claimed this was by design and their solution was to cut the power completely....Lol.