Ron,
After you've checked the Full Screen bit, though I still suggest doing a Repair Install, you do have the option of just uninstalling and reinstalling the Edge browser. When you do it this way you will likely lose anything you do not have synced to the cloud by being logged in to Edge when using it, which means everything if you've been browsing as a guest since the beginning.
You must have opened a PowerShell session elevated with admin privileges first.
To remove the Edge Browser app from all current accounts on the PC, enter the following command:
Get-appxpackage -allusers Microsoft.MicrosoftEdge | Remove-AppxPackage -AllUsers
To reinstall the Edge Browser app for all current accounts on the PC, enter the following command:
Get-AppXPackage -AllUsers -Name Microsoft.MicrosoftEdge | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register “$($_.InstallLocation)\AppXManifest.xml” -Verbose}
--
Brian - Windows 10 Pro, 64-Bit, Version 1909, Build 18363
Power is being told you're not loved and not being destroyed by it.
~ Madonna