I too have this problem on a Dell U2711 monitor connected to a 2019 Macbook Pro running MacOS 11.2.1.
It's only InDesign where I experience this problem - not Photoshop, not Illustrator, not MacOS. If I use InDesign using the Macbook I have no problem with lag but as soon as I connect my Dell I get sufficient lag to make InDesign aggravating.
I too have this problem on a Dell U2711 monitor connected to a 2019 Macbook Pro running MacOS 11.2.1.
It's only InDesign where I experience this problem - not Photoshop, not Illustrator, not MacOS. If I use InDesign using the Macbook I have no problem with lag but as soon as I connect my Dell I get sufficient lag to make InDesign aggravating.