Links to Sharepoint Document in Excel Opens in Browser

ShelliG_N Thanks for the additional information. Teams appears to be opening Office files, like Excel, in a browser-like view which for Excel gives the confusing options to open in the desktop app or just to edit or view in Teams. This is confusing for most people. If you want to avoid this, then try this approach, which is related to the current thread of opening Excel files from SharePoint.

From Teams, select the option to "Open in SharePoint." This should open a view of the SharePoint document library in the default browser--I've tested this in Edge for Excel and PowerPoint files. The first time you access this document library, see if you have the privileges to update the Document "Library Settings" (from the setting "gear" in the upper left, near your Office 365 account picture/initials), advanced settings, to select the option "Open in the client application" for "Opening Documents in the Browser." If you were able to do that, then the next step hopefully works for you.

Now click on the file you want to open in the desktop application from the SharePoint Document Library (not from Teams), and it should open in the desktop application. This works for me using Office 365 E3 / Excel (and PowerPoint) / SharePoint Online (modern experience) / Edge (v.83.0.478.37) on a Windows 10 Pro (v.1909) machine. But as you can tell from this thread, your mileage may vary--even if you have exactly the same setup, SharePoint can frustrate. And I'm not sure that it less confusing to users to have to go to the SharePoint side of Teams before opening a file, but at least they won't have both the Teams and the Desktop app showing them the same file (really confusing).