[Bug]: Files: Context menu for files appearing in wrong location

⚠️ 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

This bug is a two part bug.

Part one:
Right clicking on a file shows the context menu to far above:

Part two:
After doing part one, selecting the file and pressing the "..." for the selected files at the top. The context menu containing delete shows up at the selected file, instead of the cursor position:

This only happens if part one is executed before

Steps to reproduce

1. Right click on a file
2. Select the file
3. Press "..." for the selected file

Expected behavior

Context menu appearing close to the cursor

Nextcloud Server version

master

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

This happens at the nextcloud conf instance https://conf.nextcloud.com/ running version 30.0.0.14

I'm running Firefox 128.0.3

Start by reproducing the two-step context-menu behavior in the Files interface with Firefox, as described in the issue. Trace the positioning used by the file context menu and the selected-files “...” menu. Done means both menus appear close to the cursor after reproducing the listed steps, with coverage for the interaction if the project’s existing tests support it.