Impress - Blurry font when doing a slide show

The font looks fine when being created, but when I go into slide show mode to present it the font goes very blurry.

Here’s a screen grab when I’m creating the slides:

Here’s a screen grab when in slide show / presentation mode:

I hope that makes sense, though let me know if not!

Any help appreciated. I have searched around for an answer for some time without success.


What size is the slide?

It stays blurry even if I change the slide size. I changed the slide size to 16x9 to match the screen proportions and the font was still blurry in presentation mode. Weird.