I know of two ways these symptoms can happen. One is to do with SU Podium, and whether you have a mixture of versions installed. Their plugin in installed into:
Look in there to see if there are both 2.5 and 2.6 files. If there are, manually delete all of the files in the folder, then run the installer for the version you want to use. Or, use their uninstaller application, then their installer for the version you want.
This steps have fixed the problem for quite a few people.
If that doesn’t work, or you don’t have any SU Podium extensions, another problem that gives the same symptoms is where SketchUp fails to find the assigned GPU correctly. With Windows 10 build 1903 that can happen in different ways. A quick test to see if that might be the problem would be to run Windows on only the laptop’s internal screen, with no extender monitors or docks connected. If that then works, you may need to reinstall graphics drivers, or try SketchUp opening on a different monitor.