People having issues with picking up stuff

Just like a couple of months ago I get random players telling me they can't pick up stuff and they can't drop items. The items will disappear under the ground.

Not everyone has it and they seem to be able to pick up stuff when they jump weird... anyone an idea?
[DOUBLEPOST=1527427380][/DOUBLEPOST]When dropping stuff:

Code:

(15:22:11) | Invalid Position: generic_world[26662566] rope (world) (81.5, -507.8, 103.9) (destroying)
(15:24:10) | Invalid Position: generic_world[26669592] sulfur.ore (world) (90.6, -500.5, 113.3) (destroying)
(15:25:26) | Invalid Position: generic_world[26673862] pickaxe (world) (81.3, -501.3, 118.1) (destroying)