Hi @Mattw112IG ,
Could you please share a bit more about the "Imported Excel Connnection"? Is it the "Import From Excel" connector?
The "Import From Excel" option is used to load static data from Excel into a canvas app, the loaded data would be stored in memory of your canvas app.
And the Imported Excel connection is a Read-only data source, which could not be modified within canvas app itself. In other words, you could not write data back to this Imported Excel connection data source from your canvas app. Instead, you could only add records into this Excel file manually, then remove the Imported Excel connection from your app, then re-add it again.
As an alternative solution, please consider store your Excel file into a cloud storage, e.g. OneDrive. Then you could create connection to this Excel file hosted in OneDrive from your canvas app, and you could write data back to this Excel file directly from your canvas app.
Create an app from Excel table
Best regards,