EU Dimmers

I have two dimmers, ordered at the same time.

They both 'work' (wifi a bit of a pain, but now connected and turning on and off).

However, one has the central button blue, and the other not.

Is this a difference in the Tuya MCU firmware? Is there some way to upgrade the firmware of the Tuya MCU? Or a TAS config which should be different between the two?

br,

Simon