AR156 – Motor temperature only 50degrees

Moin together, first of all a happy new one afterwards. Me or my Alfa has caught it (unfortunately) again, my engine temperature does not climb over 50-55 degrees (before that around the 70-75 degrees in normal operation and the heater does not really warm me up either. I mean to have read older posts before, but did not find them quickly. Can you help me again on the jumps. What can it be, what should be done, how expensive for example? Greetz M.