Help needed with unresponsive matter (thread) device

I hope someone can help, although this is really more to do with Alexa/Amazon Echo than Home Assistant.

I have an Aqara U200 smart lock. I connected this to my Amazon Echo 4, as this is the only thread border router that I have. In addition, I shared the U200 with HA. Everthing was working fine.

A while ago I had an incident where Alexa could no longer control the U200 and the Alexa app wa showing ‘Device is unresponsive’.

I had a bit of a struggle to re-pair the device. I even reset the lock. This was annoying beause then I had to get everyone to rereigister their fingerprints.

Today, the U200 has gone ‘Devise is unresponsive’ again. What is the correct way to re-pair a matter/thread device with Alexa? So that I don’t reset the lock again.

I think it may be a range issue that is causing the problem. My Echo is about 6 m away from the lock with a masonary wall in the way. Maybe I need to get a matter/thread dongle for my HA host that will be closer.

So, the answer was quite simple.

I moved the echo close to the lock - just temporarily - and it started working again. I’ve moved the echo back to its normal home and it’s still working for now.

I’ll have to look into a thread dongle for my HA host.