I’ve done some tests.
I’m on a laptop here 1920 x 1080 but I’ve set the system scaling to 125%.
Cubase scaling set to -25% so basically it’s 1920 x 1080, when opening SL ARA it happens the visual artifact while setting the system 100% and Cubase normal, everything is fine. Any other change leads to the artifact. This means that SL and whatever ARA is slave to the system settings and not to the Cubase scaling, I hope this test will be helpful to find a fix.
Is your system scaling set to 125%?