White pop up box appear when connected to external monitor

One of my client is experiencing an issue with PDF documents when they try to connect/disconnect their laptop to an external monitor.

A white pop up box appears on the PDF and doesn't get removed unless all PDF documents are closed. This pop only appears in the PDF thats open and doesnt show up in the desktop or any other applications.

The user is using Adobe Acrobat Pro DC and I have already tried the below changes but no luck:

Edit>Preferences>Page Display and change the settings under Resolution, then under Rendering, select the options available and unchecked.

Then under Page Content and Information select Show large images.

Also the below change as well:

1. Go to Acrobat>Edit>Preferences.
2. Under Categories, in the Preferences dialog box, select Documents.
3. Choose the Never option for View Documents In PDF/A Mode.

Already tried repairing. Any other change I can try before I try to reinstall the software?