I am confused as this issue hasn't been reported by now, because it happend to my whole squad from time to time.
The issue is, when I have a weapon in my hand, after a unspecific time, I can't interact with it anymore, i.e. aiming down the sight, shooting, reloading, etc. until I reconnect. It happened with several weapons: PM-73 RAK, MP5, AKM, AUG, Magnum, Skorpion.

Additionally, I am unable to interact with the Mosin all the time. I don't know if it is connected but it seems that way (by means of behaviour). When carrying the Mosin on the back, it's icon in the inventory behaves like a melee weapon (e.g. the firefighter axe).