Expected behaviour of cached files in the iOS Files app

I've been trying out the iOS app with my ownCloud instance. If I preview a file in the Files app, e.g. a text file, then go edit that same file on my PC, sync the changes, go back to the Files app and preview it, it's still using the same version it cached when originally previewed. I can get around this by previewing the file in the ownCloud app, then opening it in the Files app. I can also get around this by changing the caching time in the ownCloud app settings to 1min, entering the ownCloud app to check for changes and force quitting the Files app. As you can tell this is a bit messy and manual.

Is this the expected behaviour? Or is it a bug in the background refresh? Is there a specific amount of time before the app will do a background app refresh?

If I work solely in the ownCloud app everything functions fine, but it is nice to be able to use the Files app for things like this. Also the Files app works fine for files that aren't cached or have never been opened. It's only files that are cached on iOS and then changed on another system.

Apologies if this is a known limitation, but I haven't had much luck finding anything about this online. I do know that this sort of behaviour does not happen when using other Files compatible cloud provider apps like dropbox, onedrive and gdrive.

Client

iOS version: 13.1.3

ownCloud app version: 1.1.2

Device model: iPhone 7

Server configuration

Web server: Apache

Database: SQlite

PHP version: 7.3.11

ownCloud version: 10.3.0

Start by reproducing the cached-file scenario in the iOS Files app using the reported iOS 13.1.3, ownCloud app 1.1.2, and ownCloud 10.3.0 versions. Investigate the background refresh behavior for files changed externally; done means establishing whether stale previews are expected or identifying the refresh behavior that needs changing.