We were previously on Sage 100 2018 Advanced and just upgraded to Sage 100 2020. In the previous version, users were able to put a PDF on a network share that is mapped locally on their machine to a drive letter. Then they would navigate to that file using the memo attachment tool and select it. Any time in the future, they could go in and click on that attachment and it would pull up without issue. Now however, since the upgrade they are unable to do that. Every step works exactly as it used to, EXCEPT when the click on the attachment to view it now nothing happens. No error, no attachment.. just nothing. The link is correct, their drive is mapped properly, and they can easily get to it manually inside the mapped drive letter without issue.
As a test, I uploaded a pdf to the UNC path instead of the mapped drive letter, and they are able to open it that way. What has changed that would prevent mapped drives from working within Sage? Is there some setting, or permission that I'm missing somewhere. The memo manager permissions are all set properly for the modules we use.