Each time I open a document, I get added as another co-author

Describe the bug
Every time I close out of a document and re-open it, I get added again as a co-author. It doesn't matter if I click the X or go to File ⇾ exit, I still get added again as an additional co-author every time I open a document. I opened and closed a document and got up to 30 co-authors before it started crashing.

I am also not sure if there is a way to set an idle time or not. I tried waiting 40 minutes, but all the co-authors are still there. I let it run overnight and they did disappear then.

The issue is kind of 2 fold. 1, Nextcloud is not telling Office Online that I am the same user, and 2 - when you close the document, the users are not dropping from the document.

This happens on all document types.

To Reproduce
Steps to reproduce the behavior:

1. Open a document
2. Close the document
3. Reopen the document.

Expected behavior
NextCloud needs to tell Office Online I am the same author, even if I close and reopen the document. ALso, when I do close (or there is a timeout) it should log me out of the document.

Screenshots

Client details:

• OS: Windows 10
• Browser Chrome
• Version 86.0.4240.111
• Device: Desktop

Server details

Operating system:

Web server: Not sure - Using the Hansson IT Nextcloud VM

Database: PostgreSQL 12.4

PHP version: 7.4.3

Nextcloud version: 20.0.1

Version of the officeonline app 1.0

Version of Office Online server
2019

No implementation files or tests are identified in the issue. Start by reproducing the open, close, and reopen sequence in the Office Online integration, then trace the user identity and document-session handling described in the report. Done means reopening does not create another co-author and closing or timing out removes the user from the document.