Access Security Warning

I am using Access from Office 2019 and Windows 10

I want to open PDF documents from an Access form

I can open the documents however I always get an annoying pop up message:

"Microsoft Access Security Issue"

"A potential Security Concern has been identified"

"This Location may be Unsafe"

Although if I click 'Yes' to "Do you want to continue?" it does open the document

HOW DO I TURN OFF THIS EXTREAMLY ANNOYING POP UP MESSAGE?

I have made all the correct selections in the Trust Centre

I have made the document Folder a Trusted Location

I have ticked 'Allow documents on a Network to be trusted'

Can anyone please help or advise?

I have seen several on line forums that indicate I am not alone with this problem and many people have the same issue that they cannot solve.