Failed to save thread network credential — persists through full HA reinstall (4x Aqara border routers)

Posting as a new thread since I have new information that rules out most of the usual suspects — happy to link this alongside the existing thread with the same error, in case it’s the same root cause.

Setup: Home Assistant with an existing working Thread network (MyHome6xxxxxxxx) running on 4 Aqara border routers(1x Hub M3, 3x Hub M200) — existing Aqara Thread devices work fine. Trying to add a new, non-Aqara Matter/Thread device fails at the very first step, before any pairing details are entered.

Error: “Failed to save thread network credential, error: Thread network credentials does not match with any of the active thread networks around.”

What’s new: I’ve now done a complete Home Assistant OS reinstall (fresh VM, fresh disk, restored only from a Home Assistant backup) — the exact same error occurs immediately, on a system with no possible stale local state, corrupted keychain entries, or leftover cache. This strongly suggests the bug lives either in the Thread integration’s handling of multi-border-router networks, or possibly gets carried forward inside the backup/restore of Thread credential data itself — either of which would be useful for a maintainer to know.

Also tried, no change:

  • Deleted Apple Keychain Thread entries via Companion App → Settings → Debugging → Thread
  • HA’s Thread page (Settings → Devices & Services → Thread) correctly shows the preferred network with all 4 border routers listed
  • “Send credentials to phone” directly from the Thread page fails identically
  • Fails identically on two separate iOS devices (iPhone and iPad)

HA Core version: 2026.8.2
Companion App version: 2026.7.4

This blocks adding any non-Aqara Matter device entirely. Would very much appreciate any pointers, or confirmation this is a known issue being tracked — happy to pull diagnostics/logs.

Question for clarification, are you adding this device via Aqara App and thus trying to commission it first to an Aqara Hub?