First time we have talked I think. Welcome.
I think that the most effective way to fix that resolution problem is via PCC.
Click on PCC button > enter the Admin password when requested and then click on Hardware.
Go to Configure Video Card. In the second line it says Monitor. I chose, for my laptop
Flat Panel 1366 X 768
In the third line, where it states Resolution, select Other (if the resolution you need is not shown). Down there, you will see heaps of resolutions listed. That's where I chose 1366 X 768.
After selecting your required level, you will need to exit from PCC and then Log out. There is no need to reboot, but at least a Log Out is required to make the changes stick.
Next Log in should see your resolution problems solved.