Hello there, this is Suganya. I'm an Independent Advisor and user like you. I'm happy to help you.
I'm sorry to know that you are experiencing an issue with the screen flickering on the startup of your computer.
For how long you have been facing this issue? Also have you made any software or hardware changes before the issue gets started?
Most likely your computer graphics card will cause this issue. Since you have already tried to update and roll back the driver, let us uninstall and reinstall the driver and check out the issue.
To Uninstall your display driver
In the search box on the taskbar, enter device manager, and then select it from the list of results.
Select the arrow to expand Display adapters.
Under Display adapters, right-click the adapter, then select Properties.
Select the Driver tab, and then select Uninstall Device.
Select the Delete the driver software for this device check box, and then select OK.
Restart your device and Windows will attempt to reinstall the driver.
I hope this helps you to resolve the issue. Please let me know if you need further assistance. Thank you!
Regards
Suganya