Factorio Forums

Factorio 2.0.9, no DLC, no mods
Creating a blueprint, if you adjust the grid position, then remove entities from the blueprint (by right-clicking on an item, like lights) the last grid position value you updated will 'undo' to its previous value.

prerequisites:

• blueprint contains rails
• Grid adjustment is an odd number

Steps to duplicate:

1. Create a blueprint that contains rails
2. Check the "Snap to grid" checkbox
3. Modify the X or Y grid position, entering an odd value
4. Remove an object from the blueprint (either by right-clicking the list below the grid values, or by clicking on it in the blueprint).

This is not a bug, this is intended behavior. Rails need to conform to the 2x2 grid, and blueprints get adjusted to follow these rules.
If you tried saving the blueprint after step 3, it would have given you an error.
If you want to keep the odd grid position, either pick an odd absolute position to match, or switch to relative positioning.

I understand that it is intended behavior due to rails, but having the error in both situations would be clearer rather than a silent response in one and an error in the other.