[Bug]: Files - video playback downloads file on every playback (Firefox)

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

With Firefox: When playing a video file in Files, it appears the file is downloaded/buffered again on every playback, i.e. the video plays, finishes, then playhead goes back to 0:00. Hit play again, and the files is downloaded anew.

Steps to reproduce

1. Files > open video file
2. play the video to the end
3. hit play again.
4. wait for file to buffer again.

Expected behavior

Expecting the file to be stored locally for instant playback instead of downloading on every "play"

See repeated 9.71MB download:
(Note, ignore the two other large video downloads, those related to nextcloud/viewer#2586 )

Nextcloud Server version

30

Operating system

None

PHP engine version

None

Web server

None

Database engine version

None

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

Nextcloud 30.0.1 RC1
Firefox 130.0.1

Reproduce in Files with Nextcloud 30.0.1 RC1 and Firefox 130.0.1: open a video, play it to the end, then play it again. Compare network activity for both playbacks; the issue is done when the second playback no longer downloads the video again.