I have mostly figured out how to set up my heating system, but one thing still eludes me, and that is the thing with the mixer setting. The system has 2 settings "Heizkreis Ohne Mischer" and "Heizkreis mit Mischer", which have individually programmable times. Currently both are set to come on at the same times - 5.30 - 22.30. After 22.30 it goes into reduced power mode.

As I understand it, with a mixer, you are mixing the heating circuits cooler backflowed water with the hot water and then pumping it to the radiators, fundamentally regulating the temperature so that it is not scalding hot. And without the mixer, it goes straight to the radiators. Although since they are both set to the same time, I am a little confused as to how that works. At the moment the radiators are a lot hotter at nighttime in reduced power mode than they should be. It is set to 14° in the night, but the radiators are much hotter than in the day.

I don't fully understand it. Using the mixer seems to me to be innefficient, but there is probably a good underlying reason which I have not grasped.
Should these settings be set to the same times, or should I set mixer to be on in the day, and without mixer in the night (or other way around)?

Thanks in advance