I was endorsing the other teams and I have been for a while I endorsed 3 people then my endorsement went down from 3 to 2 after I endorsed someone
I may have this wrong, but I think endorsement level is based upon how many you receive, not give.
Endorsement level is based on getting endorsed, not endorsing people. Otherwise, you wouldn’t even need to be a good teammate, you could just endorse everyone.
Another thing to note is, and I didn’t know this until my level went down, then up, then down again, your level can decay over time if you don’t receive enough endorsements per number of matches (I can’t remember the number, 4-5? 10?).