Medic bag bug

I have had some problems when spawning and suddenly loosing some health without getting shot at (down to like 20% health) and when i place a medic bag my health does not go up. Happend maybe 4-5 times during the 10 fist games. Friendly medic bags does not help and not my own, i have to get killed in order to get 100% health again. Have anyone else had this issue?