Cursor disappears (only) over the italic texts (on PC)

I've just started encountering this bug having moved from a Lenovo laptop with two external screens to a Surface with two external screens. The Surface has a retina (to use Apple's term) screen, the external screens are non-retina. On the Surface screen when the cursor goes over italic text it halves in size, becoming much finer, as though it's forgetting to use the pixel-doubled version. If that is replicated on the non-retina screen, presumably it would disappear. 

Probably related: on both the retina and non-retina screens when I put the arrow cursor into the left margin to get the right-pointing line-selection arrow cursor, it halves in size - I can see it, though, because it's so much chunkier than the I-beam pointer. 

Oddly enough I didn't encounter this on the Lenovo, which also has a retina screen built-in (but with non-retina external screens). 

It seems that Word forgets to use the retina version of its custom pointers, and can't tell if it's on a pixel-doubled screen or not. Goes along with Windows' pretty uneven handling of pixel-doubled screens, but really should have been identified and fixed if the longevity of this forum post is anything to go by. 

Edit: And, in fact, I find now that the little mickey-mouse gloved hand pointer for links is half-sized in Outlook. Seems it might be an office-wide problem.