After installing a 3 way on my Artika Skylight flat LED panel (dimmable), the panel slowly goes from being bright to dim and then off as if the dimmer button was pressed but both switches doesn't look

I have been using KS230 KIT 3 Way dimmer switches in our living room and in our bedroom for the past 9 months. Since the past 3 months, the lights have started to auto dim from 100% to 85% to 68% to 5