Yes, I have seen this too. I'm 10 points clear in the League, in the Cup semi and CL quarters with an awesome team hoping to get my first treble. Yet I still leak goals inexplicably. I rarely have a clean sheet in fact. Hence my GK often gets a 6 rating when everyone else gets 8 or 9. I'd blame my GK but the other one is the same. They both pull out a few saves during the game. So it is odd indeed.
KFC Loella. Level 30
16 League Titles
3 Champions Leagues
1 Cup