(Why) Are GK ratings slow to update?

[LeManiaque]

I was ready to pull my GK all game because his rating looked so low. Of course the final result rounds up to an 8 on his stats sheet. That's a big disparity. The other full-time players ok those 2 screenshots you can see the difference is tenths of a rating point, while GK is a full point....

I know stats often don't update during game (return to home menu and re enter match if this is your problem), but could this mean GK has another calculation that can only happen after the game? For example part of the GK reading formula could include (GK base rating+[average defender rating X a GK communication factor]).