I mean I might be the way to fix it by turning it on. Probaly not though. Could you inlcude a video of the flickering? Does the flickering only happen in games or just anytime. (Vsync would only work for games)
you could get a GPU enclosure if that laptop has thunderbolt 3 (I would assume it does because it is a newer gen laptop)
Would look something like this:
I mean IF your dad installed parental control software I am not in a place to turn that off, he is your parent and it is his prerogative to make those decisions. why dont you ask him what he did?