I had the same issue where UWB wasn’t responding — this setup resolved it:
• Use an Apple TV 4K (3rd generation) Wi-Fi + Ethernet as your Thread Border Router (TBR) and place it within ≤3m of the U400 (mine is directly above it).
• In Apple HomeKit, ensure this Apple TV is the active/primary TBR (avoid suboptimal TBR selection).
• Create a dedicated 2.4 GHz SSID with IPv6 (SLAAC) enabled on your router.
• Connect the Apple TV to Wi-Fi first, then plug in Ethernet (ensures stable backhaul while maintaining correct network association).
• If using Ubiquiti gear, deploy multiple wired APs (no mesh uplinks) for consistent RF coverage.
Also:
• Disable Auto-Lock in HomeKit (stateless timer-based)
• Configure Auto-Lock in Aqara Home instead — it’s state-aware and won’t lock when the door is open