While playing, I found it impossible to aim down sights with any of my firearms. I could hipfire with all of them, but not a single method of going into ADS worked. Putting a weapon on the ground and then straight into my hands fixed the issue, but strangely it immedeatly forced me to do a firearm melee attack without me doing any of the inputs for it (neither aiming nor pressing F). Sadly I do not know what caused this.