Turns out the“Home Assistant Connect ZBT-2” can only do [Zigbee] or [Thread & Matter] not both.

Despite saying it cuts clutter & works with “Zigbee, Matter or Thread devices”. That’s an XOR not an OR.

It seems to install either Zigbee or Thread firmware, so you’ll need 2 devices if you want both.

@mattgrayyes there's nothing special about the home assistant branded dongles afaik, I'm using an AliExpress ZigBee dongle with the same Si chipset and it's been working fine except for one bulb not behaving sometimes, and I'm blaming Tuya