Ocis vs Wopi. file size is 0 after some content is posted

up ocis `3.1.0-beta.1 `with wopi using https://github.com/owncloud/ocis/blob/master/deployments/examples/ocis_wopi/docker-compose.yml

Steps:
- create a `.odt` file and put some content in it
- close the OnlyOffice tab and check the size of the file.

Actually: size is 0. After page refresh - 0 bytes
- reopen in collabora - the content exists
- share to user with view permission

Actual: user gets empty file.

https://github.com/owncloud/ocis/assets/84779829/56132a04-70a2-49b0-804b-c18c4370d69e