Artboards Glitching - rotating horizontally

Hi there,

I am having a weird glitch happening with my artboards.

For some reason, my vertical artboards have started randonly flipping horizontally. I will change it back but then it will do it again. Its across all files I open/start.

I can't figure out whats causing it. I use Illustrator daily and haven't changed anything about how I am working. I have done a computer restart. On the latest version of Illustrator, no updates available.

Not sure what else to try?

Thanks heaps in advance!