Nothing happens when sending Thread credentials to Home Assistant

**iOS device model, version and app version**

Model Name: iPhone XS
Software Version: 18.6.2
App version: 2025.7.2 (2025.1356)

**Home Assistant Core Version**

2025.9.1

**Describe the bug**
I have two Thread networks, one created by a HomePod mini and one by an SMLIGHT SLZB-MR2. I would like to join these two by first making the HomePod one the Preferred network.

When clicking on "Send credentials to Home Assistant", then Allow, a checkmark appears on the screen. However, after reloading the page, nothing has changed and Home Assistant has not registered any credentials (no info symbol is visible on the HomePod network). No error message appears.

**To Reproduce**

1. On the Thread integration page, click on "Send credentials to Home Assistant".
2. Click on "Allow".
3. Reload page.

**Expected behavior**
Thread credentials to be registered or, if something goes wrong, an error message.