And well known why. As you change Word as well as PCs, Word will reformat your document as it gets "hints" from the printer as to how it will show on that printer's printed page.
No mystery at all here.
What to do? If you must -> TYPESET <- then you must stop using Word. You need to move to typesetting apps.
It's that simple.
Light bulbs you shouldn't buy
There are plenty of dimmable LED light bulbs, but make sure you don't buy the ones that flicker when you dial them down.