Windows File Explorer preview pane holds PDF files open so they cant be changed

Company has server 2012R2 as a Remote Desktop server on a network. Users typically navigate to a PDF document using Windows File Explorer, check its the right document in the preview pane then double click on it to open and edit it in Acrobat. The document can be edited but they cant save it while the document is displayed in the File Explorer preview pane ("File in use. Try again" error). They have to close File Explorer or select a different file in File Explorer before they can save the edited document.

• Acrobat is default PDF viewer.
• Latest version of Reader and latest version of Acrobat 2017 are installed.
• All Windows server 2012 updates and service packs installed.
• Have repaired Acrobat and reader
• Does not happen with Microsoft Office documents or other tested document types.
• Can recreate the issue using only Windows File Explorer by opening 2 x File Explorer windows and highlighting the same document in both. Try to delete the file in either window and get "File in use. Try again" error. Close one of the File Explorer windows then can delete the document.

This customer needs to use the preview pane otherwise I would just recommend it be turned off.

Would appreciate help diagnosing this.

Thanks.