Upgrading Snaking Sands only increases its critical damage and amount of charges, but not its damage.
The displayed damage on inspection is also not correct.
The actual damage is higher.
Looks like this just relates to the inspect tooltip as the actual damage done it being increased with each upgrade. Are you seeing the damage not actually increase when you upgrade it?
Okay, the damage increases with upgrade the display/inspection is just totally wrong.
The displayed damage on inspection is also not correct.
The actual damage is higher.