What version of CB, what operating system?

Do you have an older video card? If so check out the "Graphics card backwards compatibilty mode" on the Main menu|Setting dialog;

If you have a newer "bleeding-edge" system it may be that the QT development system does not yet support your platform. You might ewant to try compatibility mode anyway...

I am using v1.9.3 and also have this wierd issue. I have updated the Graphiccard driver from a LG Driver to a Intel Driver without improvement. My System has only a Intel Iris Xe Graphicscard. 
Please fix this. I am getting crazy and I am trying to like chitubox... but with all those flashing and stuff i think i have to use LycheeSlicer :(