Your description of the problem indicates it is just the View in File Explorer that may be corrupted.
Open File Explorer, then on the top menu, click the 3 dots and select Options.
On the resulting utility, on the General tab, click 'Restore Defaults'.
Select the View tab on that utility, then click the Reset Folders button and the Restore Defaults button.
Apply those settings, then close and re-open File Explorer to test of that resolves the problem.
If not, in the left pane in File Explorer, right click an empty spot, on the resulting menu are a few view options, try toggling each one on/off to test if you can restore the correct view in that navigation pane.