[OBSOLETE] Lidl Smart Home DTHs

I got the RGBW bulb working nicely with the custom device handler (now also able to change color which didn’t work with Zigbee RGBW). However, the brightness is very low when in color more. In white mode in any color temperature it works as expected. Is this due to the bad quality of the bulb itself, or something related to the DTH? Does anyone else have the same issue?