When my colleague is sharing his screen it takes a long time for the screen to actually render properly, and as soon as he starts scrolling it gets all blurry again.

He's on a decent internet connection. This haven't happened before. He's not maxing the connection either, so it doesn't feel like it's because of the connection, but how screen is using the network.

If he stops the share and then re-share the screen it works for a little while, then it gets back to being super blurry again.