The grid snapping does not snap object to a grid on the specified grid size. It snaps object to an offset of the grid unit.
Create an actor at the origin 0,0,0
Set the grid size to 1
Drag the object to 5,0,0
Set the grid to 100
Drag the object to 100
It will be impossible with grid snapping on to move the object to 100, it will instead snap to 105.
The expected behaviour would be the latter where the grid snapping snaps the object to that specified grid unit. This issue is exasperated with BSP where the vertices end up offset and it becomes quite frustrating to correct them.
I don’t see how the method I described as expected behaviour invalidates the typical use case you describe.
The current workflow merely creates confusion because if you accidentally move something when your grids are on the wrong scale, you inevitably have to either do the offset math in your head to get back to the right grid scale, or reset your object back to zero, set the grid scale to the correct and re-position your object
All this behaviour does is punish people for having their grid set incorrectly to the convention of the team. What if I my saved config gets deleted and I start working for a couple hours on something organic before I realize my snapping is off?
Also this is counter to the behaviour is all the 3d packages, photoshop and countless other dcc tools.
The description on the button is “Enables or Disables snapping to the grid when dragging objects around” which is also an incorrect description for the current workflow.
This is actually not an incorrect functionality. What you are doing is when you change the grid snapping to 100 and move the object to 100 (because you changed your orgin when changing the snapping at 5,0,0 instead of 0,0,0) it will move to 105. When working in a project you usually don’t want to change around the grid sizes and snapping with different values because it can cause your things to become offset like you are experiencing. You typically want to find a grid snapping value that works best for the project you are working in and stay with that.
This is why when you create a project with a team you set up metrics, which forces everyone else to work within the same grid so no offsetting occurs. There are other ways to fix the issue instead of doing the math like using snap to objects or vertices of objects within a radius.
I am also not sure why your saved config would get deleted for no reason and you would work in that project for a couple of hours going unnoticed? I am simply just trying to inform you that there are other work around’s in case your grid snapping does get offset, and why your initial issue was occurring.