Weirdness with new Photoshop Update

The main thing I am noticing is weirdness with the Marquee tool now that I have updated to the newest version of Photoshop. When I try to make a circular Marquee for example I don't get a clear outline of the shape, just lots of glitchy dots in the centre of the screen. I can only see where the Marquee shape was if I fill it with a colour.

Also, when I draw a freehand selection area with the Lasso tool it has a delay, so the actual lasso takes a few seconds to appear after it's been drawn, which is irritating and makes you think it hasn't worked.

I also notice that the lasso/marquee edge line looks thinner than it used to and I don't like it, it's harder to see on screen.

Thanks.