We are sorry for the trouble and the delay in response. I hope you would be able to fix it by now. If the issue still persists, please update the application to the latest version 20.12.20048. From the help menu > check for updates and see if that works for you.
If it still doesn't work, do you have the Preview Pane enabled in File Explorer? If so, can you disable it temporarily to see if the problem goes away? On Windows go to file Explorer go to the View tab, and if the "Preview Pane" button is pressed, If yes, un-press it and check if that helps.