Drag & Drop assignment of Contacts only works reliably when marking the contact first.

Describe the bug

Hi NC Fam!

I found a weird behaviour that "most of the times" when dragging and dropping contacts, without priory highlighting of the entry.

I was able to reproduce this on Brave / Chromium engine, Safari and Firefox. Seems a global issue, not browser-related

Steps to reproduce

1. Go to 'Contacts'
2. Have a group you want to add users to
3. go to "ungrouped Contacts', directly drag and drop users into the new group
4. It seems like the change is committed, however, when reloading, most of the contacts added to the group won't be stored.

Expected behavior

Contacts should be saved properly, as the UI indicates.

Actual behavior

Contacts are displayed in the group until you reload. Changes then are gone.

Contact version

8.3.7

Operating system

osx

PHP engine version

PHP 8.3

Web server

Apache (supported)

Database

PostgreSQL

Additional info

As this is easier to understand by seeing the behaviour, ive created a short screencast demonstrating.

https://drive.google.com/file/d/1xTpLw7RYyQy4LNn5jiOgd-55DM1vNAH_/view?usp=sharing

The Event that is "NOT" Triggered is the PUT Event with the VCF on https://nc.horst/remote.php/dav/addressbooks/users/admin/contacts/[contactId.vcf]

Truncated Curl (Cookies, Tokens anyonymized)
curl 'https://nc.horst/remote.php/dav/addressbooks/users/admin/contacts/08EA2FDB-18FD-44FA-A617-C5BF8E1CEC99.vcf' \ -X 'PUT' \ -H 'accept: application/json, text/plain, */*' \ -H 'accept-language: de-DE,de;q=0.7' \ -H 'cache-control: no-cache' \ -H 'content-type: text/vcard; charset=UTF-8; charset=UTF-8' \ -b 'oc_sessionPassphrase=b8...co; __Host-nc_sameSiteCookielax=true; __Host-nc_sameSiteCookiestrict=true; o....d9; nc_username=admin; nc_token=37....qF; nc_session_id=19....d9' \ -H 'depth: 0' \ -H 'if-match: "c...."' \ -H 'origin: https://nc.horst' \ -H 'pragma: no-cache' \ -H 'priority: u=1, i' \ -H 'requesttoken: iq....arU=' \ -H 'sec-ch-ua: "Chromium";v="146", "Not-A.Brand";v="24", "Brave";v="146"' \ -H 'sec-ch-ua-mobile: ?0' \ -H 'sec-ch-ua-platform: "macOS"' \ -H 'sec-fetch-dest: empty' \ -H 'sec-fetch-mode: cors' \ -H 'sec-fetch-site: same-origin' \ -H 'sec-gpc: 1' \ -H 'user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36' \ -H 'x-requested-with: XMLHttpRequest, XMLHttpRequest' \ --data-raw $'BEGIN:VCARD\r\nVERSION:3.0\r\nFN:Hildegard Hopfensmoothie\r\nN:Hopfensmoothie;Hildegard;;;\r\nEMAIL;TYPE=INTERNET:hildi@brauerei-wellness.test\r\nTEL;TYPE=WORK:0800-BIER-HER\r\nORG:Institut für angewandtes Vorglühen\r\nTITLE:Chief Hydration Officer\r\nUID:e278ca7c-ac50-4599-a6c6-48e16bdbfd46\r\nREV:20260407T0811Z\r\nCATEGORIES:World Domination Group\r\nEND:VCARD'

Start by reproducing the Contacts drag-and-drop flow described in the issue and monitor requests to the CardDAV contact URL. Verify that moving an unhighlighted contact triggers the PUT request and that the assignment remains after reloading; the issue provides no source file or test name.