Why do I loose social rating?

[eifes]

Why do I loose the social rating I've gained? It has happend several times now, and it's really starting to annoy me.
It's not all of it, only a little bit every time.

[[S8] Regina]

The Social Rating decreases over time, and this is intended game play. In order to keep up the Social Rating at 4 (the highest), you will have to be active and tip your neighbors each day.