Bump Offset Shifts UVs?


I’ve posted this on UE answers but hoping to get some kind of answer asap.

I’ve noticed an issue with using bump offset to offset a red dot reticle for a sight. It seems the reticle doesn’t align exactly with the centre of the screen and if the offset makes the reticle appear further away, it strays towards the top right and if I shift it closer to the screen it shifts towards the bottom left.

Not sure how to overcome this issue, the only fix is to remove any offset, which defeats what I’m trying to achieve.

Thanks for any help.