Square box when selecting

has anyone been having a problem with a select tool. Occasionally when I try to select points I get a black or cream square box and I am unable to select precisely. I also noticed when this happens all selected facies are turning solid blue. can anyone help, please?

Can’t be sure from the images, but it strikes me as a graphics issue. Can you share your model so we can try to reproduce the issue?

Your forum profile information is inconsistent, so that doesn’t help clarify. SketchUp Pro 2018 won’t run on iOS, so we don’t really know what you are using. Please correct your profile.

Thank you for your reply. I am using S-UP 2021, on IOS Big Sur, with a AMD Radeon Pro 5500M 4 GB

Intel UHD Graphics 630 1536 MB

Thanks for the clarification. Please correct your forum profile so we don’t hit confusion again. There is no such thing as iOS Big Sur, it is macOS Big Sur. iOS runs on iPhones and iPads, not on Macs.

Macs are pretty good about automatically switching to the Radeon graphics when available, but check in SketchUp->Preferences->OpenGL->Graphics Card Details to make sure. If it is using the Intel UHD, check System Preferences->Battery->Power Adapter to check that Automatic graphics switching is checked.