Excel File not changing into read-write from read only when using Notify feature

Most of our users are on Office 365, and we have files stored on a windows file server. If user A opens an excel file, then user B opens that same file they have the option to notify when the file is available. Once user A is finished, user B gets a notification saying "FILENAME is now available for editing choose read-write to open it for editing". If they choose the Read-Write button it shows an error message saying "We're having trouble connecting to the server. If this keeps happening, contact your help desk". This happens between two Win10 PC and between a Win10 and Win8 PC both directions. It also happens between a PC with Office 365 and one with Office 2013, and also between two PC's with Office 365 and the latest version installed. This does not happen with Word however. Word will correctly switch to Read-Write no issues.

In my Googling, everything seems to be for SharePoint rather than a file server. I have not been able to find a solution to this issue.

Thanks in advance!