Installed ccleaner 7 and updated drivers as recommended and now both monitors display the same and do not work independently.
Try using the “+ Fix a Problem” in the Driver Updater to see if it can roll back the display drivers for you.
In this case though I suspect that changing the display driver has simply reverted your system to single display and you will need to set up the dual monitor display again.
PS, I never update drivers unless there is something wrong with the one(s) I have already.
Updating a driver unecessarily can cause things to stop working properly, as you have found.
PPS. The v7 Beta is an unfinished testing version, as such it is unfinished and may be buggy.
It is recommended that you still use the “Offical” v6.## version alongside the v7 Beta:
Could it be that the display options just reset to Duplicate from your original Extend? Can you try to check and possibly adjust that setting? Here is how - How to use multiple monitors in Windows - Microsoft Support - scroll to the “Choose a display option” section at the bottom of the page.