synchronization client V. 34.0.0 - MORE ACTIVITY window do not open on Linux Mint Mate 22.3

### ⚠️ Before submitting, please verify the following: ⚠️

- [x] This is a **bug**, not a question or a configuration issue.
- [x] This issue is **not** already reported on Github (I have searched for it).
- [x] Nextcloud Server and Desktop Client are **up to date**. See [Server Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) and [Desktop Releases](https://nextcloud.com/install/#install-clients) for supported versions.
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/)

### Bug description

Good morning. Yesterday I was testing the new version of the synchronization client, version 34.0.0, on several Linux Mint Mate 22.3 installations and some Ubuntu Mate 22.04 installations. The problem I encountered is that the MORE ACTIVITY window doesn't open in any of the versions, so I can't see any synchronization conflicts or problems to troubleshoot them.

### Steps to reproduce

1. Click on tray icon
2. Go to User Profile
3. Click on More activity
4. nothing happens

### Expected behavior

Clicking on More activitiy, we must see the new activity window.

### Which files are affected by this bug

I dont know

### Operating system

Linux

### Which version of the operating system you are running.

Mint mate 22.3 and Ubuntu 22.04-24.04

### Installation method

Official Linux AppImage from nextcloud repository

### Nextcloud Server version

32.0.9

### Nextcloud Desktop Client version

34.0.0

### Did this occur after an update or on a clean installation?

Major version update (i.e. 4.0.0 → 33.0.0)

### Are you using the Nextcloud Server Encryption module?

No

### Are you using an external user-backend?

- [ ] Default internal user-backend
- [ ] LDAP or Active Directory
- [ ] SSO - SAML
- [ ] Other

### Nextcloud Server logs

```shell

```

### Additional info

The log file shows this:
2026-07-31 09:34:52:614 [ info nextcloud.gui.account.state ./src/gui/accountstate.cpp:600 ]: Skipping server availability check for account "user" with state 2
2026-07-31 09:35:07:299 [ info nextcloud.gui.activity ./src/gui/activity/activitylistmodel.cpp:591 ]: Start fetching activities for "user@nextcloud.servver.com"
2026-07-31 09:35:07:299 [ info nextcloud.sync.accessmanager ./src/libsync/accessmanager.cpp:101 ]: "GET" "" "https://nextcloud.servver.com/ocs/v2.php/apps/activity/api/v2/activity?previews=true&since=0&limit=50&format=json" has X-Request-ID "a767eb05-43df-48e7-ac77-0169c55e75a5"
2026-07-31 09:35:07:300 [ info nextcloud.sync.networkjob ./src/libsync/abstractnetworkjob.cpp:381 ]: OCC::JsonApiJob created for "https://nextcloud.servver.com" + "ocs/v2.php/apps/activity/api/v2/activity" "OCC::ActivityListModel"
2026-07-31 09:35:07:533 [ info nextcloud.sync.credentials.webflow ./src/gui/creds/webflowcredentials.cpp:388 ]: request finished QUrl("https://nextcloud.servver.com/ocs/v2.php/apps/activity/api/v2/activity?previews=true&since=0&limit=50&format=json") with request id "a767eb05-43df-48e7-ac77-0169c55e75a5"
2026-07-31 09:35:07:534 [ info nextcloud.sync.networkjob.jsonapi ./src/libsync/networkjobs.cpp:1115 ]: JsonApiJob of QUrl("https://nextcloud.servver.com/ocs/v2.php/apps/activity/api/v2/activity?previews=true&since=0&limit=50&format=json") FINISHED WITH STATUS "OK"
2026-07-31 09:35:08:636 [ warning nextcloud.gui.systray ./src/gui/systray.cpp:291 ]: "qrc:/qml/src/gui/activity/qml/ActivitiesWindow.qml:85 Type ActivityList unavailable\nqrc:/qml/src/gui/activity/qml/ActivityList.qml:98 Type ActivityItem unavailable\nqrc:/qml/src/gui/activity/qml/ActivityItem.qml:87 Type TalkReplyTextField unavailable\nqrc:/qml/src/gui/activity/qml/TalkReplyTextField.qml:13 Type NCContextMenuTextField unavailable\nqrc:/qml/src/gui/common/NCContextMenuTextField.qml:14 Non-existent attached object\n"
2026-07-31 09:35:08:637 [ warning nextcloud.gui.systray ./src/gui/systray.cpp:292 ]: QList(qrc:/qml/src/gui/activity/qml/ActivitiesWindow.qml:85:13: Type ActivityList unavailable
ActivityList {
^, qrc:/qml/src/gui/activity/qml/ActivityList.qml:98:19: Type ActivityItem unavailable
delegate: ActivityItem {
^, qrc:/qml/src/gui/activity/qml/ActivityItem.qml:87:30: Type TalkReplyTextField unavailable
sourceComponent: TalkReplyTextField {
^, qrc:/qml/src/gui/activity/qml/TalkReplyTextField.qml:13:1: Type NCContextMenuTextField unavailable
NCContextMenuTextField {
^, qrc:/qml/src/gui/common/NCContextMenuTextField.qml:14:5: Non-existent attached object
ContextMenu.menu: Menu {
^)

Reproduce the issue by opening User Profile > More activity, then start with the QML warning at src/gui/common/NCContextMenuTextField.qml:14. Trace how that failure propagates through TalkReplyTextField.qml, ActivityItem.qml, ActivityList.qml, and ActivitiesWindow.qml. Done means the More activity window opens and displays activity on the affected Linux installations.

Written by the indexing model from the issue text.