A few weeks ago I noticed my L535B started to flicker for a split second when turning it on from the wall switch. It looks like it quickly turns a dim light blue before returning to the 3400k white I have it set at. The flicker does not happen when the light turns on using an RGB colour, and also does not happen when turning on from the phone when the wall switch is already on. This was after running a firmware update.
I initially thought it was a hardware failure but today I bought a brand new one, set it up and tested it. No flicker.I updated it once, no flicker. A second update came through, after which the flicker returned.

I've tested on all different switches in the house and it behaves the same. My brother who also has one but doesn't keep on top of updates does not have this issue at all. Clearly something in the firmware has caused this. I'm just hoping TP Link are aware and working on it. Would also be nice to know if someone else is seeing this problem. It's starting to do my head in.