I may be an idiot and the answer has been in front of my face the whole time but I cannot for the life of me get Matter over Thread working on my setup. I purchased an Aqara U200 because I've seen many people raving about them. I cannot get it connected to my HA setup.
I am currently running HAOS as a VM on Proxmox. I bought the Home Assistant Connect ZBT-1, plugged it in, and enabled USB passthrough for the dongle to the VM. I installed the OTBR add-on, selected the proper device in the config, and started the add-on. Matter, Thread, and Open Thread Border Router integrations are all installed. When I go to the Thread integration and select configure, it shows 1 border router. When I go to add a matter integration, I scan the QR code, it thinks for awhile then gives me the error shown in the post title. I am not able to access the OTBR web interface either. I've tried http://homeassistant.local:8081 and http://<homeassistant-vm-ip>:8081 and the page doesn't resolve.
Any ideas on what I'm doing wrong and how to get the OTBR working?
Thank you!