Blurry UI in UE4 (scaling/resolution)

The font in UI is blurry and annoying to read. It happened just now when I started playing with connecting Surface Pro 6 as an external wireless display. My main monitor is 1080p, second one as well and I never had problems with them. However connecting the SP 6 seem to had an impact on it as I cant get it to look the way it did before.

1080p monitor set as primary
100% scaling as recommended
tried reinstalling UE4

Any ideas?

Thanks,
Raf