Issue with Opening New Excel file on sharepoint site

Question

Hi,

I hope this message finds you well.

We have a application(third party to Microsoft) which is integrated with Microsoft in such a way that it adds a new column in the file lists in the document library. This column contains a link that, when clicked, redirects to our application.

However, please note that we have not configured a file handler for new file creation. Hence, we do not expect the behavior described below to occur:

Upon creating a new Excel file, SharePoint triggers our applications file handler (our custom app deployed on SharePoint). This behaviour is unexpected as we have not integrated any 'newFile' action with the SharePoint FileHandler. Notably, this issue does not occur with any other file types. Other file types (e.g., Word documents) are opened using the default SharePoint file handler/editor as expected.

Observations:

1. The issue is specific to Excel files.
2. When a new Excel file is created, the network logs indicate calls to 'CreateDocumentAndGetEditLink' and 'GetItemByUniqueId' functions, which seem to create the document and obtain a direct link for editing. These calls are not observed for other file types like Word documents.
3. This issue was observed around four months ago and resolved itself before we reached out to Microsoft, but it has now reappeared.Attachments:

For your reference, I have attached snippets of the network logs showing the differences between the logs for a new Word document (working correctly) and a new Excel file (triggering our application's file handler).

When New Excel file is created:

For all the other files (No issue observed):