Setting up Thread with SkyConnect

I am having an issue with using my SkyConnect as a Thread Border Router. I am currently using it to control a few Zigbee devices.

I have tried following this procedure:

But I’m having issue after step 4. The Open Thread Border Router never shows up under my integrations like it says it should.

In the Silicon Labs Multiprotocol addon log this error is printed several hundred times each second:
2023-12-26 17:27:08 homeassistant universal_silabs_flasher.cpc[188] WARNING Failed to parse buffer bytearray(b'\x14\x00\n\x00\xc4U\xd3\x02\x00\x04\x00\x03\x00\x00\x00 o~'): ValueError('Invalid payload checksum')

Does anyone have any idea what could be the issue?

The “universal silabs flasher” it trying to talk to your SkyConnect to see what type and version of firmware it is running and whether or not it needs to flash it with a different type/version. The flasher code is getting something from some device, but doesn’t like the data it is getting. Beyond that, I don’t know.
You mentioned you are currently using it to control Zigbee devices. If ZHA or anything else is using the SkyConnect at the same time you’re trying to get the SiLabs multiprotocol addon running of course would be a problem.