When I got this error, it either caused or was caused by what I'm assuming was a lack of communication with the server; I couldn't perform any action other than movement.

Seems to be happening less as of latest update, even when switching servers, character remains intact

Not an ISP problem for me. Changing router settings and Windows Firewall settings hasn't resolved the issue either. The desync only seems to apply to actions; fighting zeds works perfectly fine. Actions affected:

-Hotswapping using 1-9
-Looting
-Opening/Closing doors
-Eating/drinking
-vaulting
-turning flashlight on/off

Also, loot itself sometimes either disappears or takes a moment to appear; ie when crafting rags from a shirt on the ground, the shirt disappears, the rags do not show up, neither in inventory nor on ground