Hi, maybe someone can help, I have an Ultra wide monitor 3440x1440 and a rtx2080 super, today the computer appeared with a lower resolution, and Windows or the Nvidia control panel will not detect the full resolution.  Tried with a different videocard and the same.   Windows just installed several updates, and Razer control panel also updated several times.  I dunno what to do, reinstalled drivers and the same thing. 
I dunno if its the monitor, the cable, or the updates that messed up.  what could be?  Iam about to reinstall  Windows but I will loose info and time. Any clues what could be, anyone have happened this before. thanks

Listing your specs always helps in troubleshooting.
 
First of all see if your monitor has an HDMI cable connection. If using a DP cable disconnect it temporarily for troubleshooting. If you have an up to date TV in the home you're probably using an HDMI cable to the TV box. Borrow that cable and use that cable to the video card and monitor to see if this resolves the issue. If it does then you know it's the cable

thanks RJ!