Modified files in Word (iOS) not updated on server

Expected behaviour

Opening a file in Word (on iPad) from Nextcloud should upload the changes to Nextcloud.

Actual behaviour

When a file is updated in Word (iOS), the updates is not pushed to the server and are lost if the file was in the NextCloud client cache.

If the file is removed from the client cache, all editing in Word works (updated files is pushed on the server) until the client is launched. Then, all future updates are lost until the file is removed from the client cache.

Steps to reproduce

1. Create a Word document (using a computer) and send it to NextCloud
2. On the iPad, open the document from Word
3. Makes change to the document and quit
   a. The document should be updated and new modifications should be visible on the computer if the file is opened
4. Open the NextCloud client on the iPad
5. Return into Word on the iPad and makes new change
   a. The change should not be visible on the computer
   b. If the file is reopened in Word on iPad, the changes are lost
6. Open the NextCloud client and delete the file from the local cache
7. Open Word on iPad and makes change on the file
   a. Changed should be updated in NextCloud
8. Opening NextCloud client again should break the file until the cache is cleared again

iOS version

12.3.1

App version

NextCloud client 2.23.7.9

Server configuration

Operating system: Ubuntu

Web server: Apache

Database: PostgreSQL

PHP version:

Nextcloud version: (see Nextcloud admin page) 16.0.1

Start by reproducing the Word-on-iPad workflow with a cached Nextcloud file, comparing behavior before and after the Nextcloud client is launched. Trace the iOS client’s local-cache and external-document synchronization paths; done means edits made in Word are uploaded and remain available after reopening the client and document.