During character creation did you by chance increase or decrease the avatar size? No confirmed link to this yet but I have suspicion that the modified z-axis scalar isn't always being loaded correctly and sometimes loads the z-axis scalar of a default avatar with your increased/decreased size. This would cause current z-axis <-> object collision with body to fence with each other and constantly have to auto-correct themselves. EX: 1: You get a dirty scene load with incorrect z-axis scalar size for your larger than default avatar size. Or maybe Dev team overlooking z-axis scalar and forgot to link it to the character size slider along with the player skeleton/mesh/layers. 2: You load into the scene and your feet touch the ground, this forces your z-axis to -0.05 (theoretically) 3: You go swimming 4: After a while the Z-axis corrects itself returning to a state of 0 since there are no longer any object collisions to prevent that from happening. So this puts your z-axis at 0 but physical body at +0.05. 5: You return to shore but feet never touch land because they are hovering +0.05 above the ground so your swimming tag never clears. 6: Run around for a while and your body's lack of collision finally kicks in and adjusts your position back to ground level moving your z-axis back to -0.05 So the 2 different systems fight with each other back and forth. Sometimes fencing resolves itself almost immediately as soon as it has an out, other times it backlogs code that takes time to finish processing once an out is presented. Collision obviously would be the ultimate rule setter so when on land the z-axis has to obey, but out in the water they can fight. The longer you swim, the longer the 'fencing' (techy term) takes place and puts a backlog in the code that determines your z-axis position. When you return to land, the longer the backlog of code is, the longer it could potentially take to auto-correct itself. I have a suspicion if this theory is correct than players with significantly smaller than average body size may fall through the water sometimes when they go swimming instead of hovering above the ground when they return to land.