Artefacts in presentation mode

Suddenly when in presentation mode I get weird dark lines around areas that are not there in the actual design, see attached images. What’s causing this, it’s terrible!


Could be the same issue like:

Thanks but I’m afraid that’s not the case. It started happening suddenly without having changed anything and the background colour is not black.

just to be sure I double-checked the position of all the elements and there are no subpixels anywhere.

There were similar reports here:

How does it look in different browsers like chrome or firefox?