Shift and Ctrl keys work inconsistently in Firefox

Hi! I’m using SketchUp Free, and when I press Shift or Ctrl buttons, they sometimes change mode of a current tool and sometimes not. I’ve also tested this behavior in Chromium, everything works fine (except for the hardware acceleration, but that’s a Chromium issue). Disabling all extensions in Firefox also doesn’t help.

Nevermind, seems like it was some system update issue, everything works fine after reboot.