I tried dragging a new backpack onto my character that was already wearing a backpack and it bugged my character so I couldn't move or do much of anything such as land melee attacks. I was playing the new 0.63 experimental build after BattleEye was enabled. I had a green taloon bag on my back and a 1-handed hatchet in my hand - I approached a dead body and tried to drag their hunting backpack onto my characters body in the inventory screen - the new bag icon showed in my inventory for a second and then snapped back to the dead body. That is where the bug started. I dragged the new bag onto my characters upper body area inside the inventory screen (I did not properly drag the new bag icon onto my existing bag icon). I was then stuck in the ground and my melee didn't seem to do damage and my Makarov bullet did not land. A friend said on his screen I was holding the new hunting bag from the corpse. I left the server and rejoined and it fixed the issue - I logged in with the hunting bag in my hands. I will link a time stamp to my stream since I have it recorded. It has happened before in 0.63 for me as well. Last thing; there were 2 dead players next to each other when we found the bodies with the hunting bag - one killed the other with a single shot FNX pistol and the other bled out or was killed by a zombie. There were multiple dead bodies and zombies and players in the area.

Twitch VOD link to the moment it happened:

https://www.twitch.tv/videos/274813741

(Start at 09:04:50)