Errors - "Connect to cloud: -8"

I am attempting to connect a Shelly1 relay to the "WarmupWSM" system. This device has been integrated into a Warmup-252W device to provide cloud connectivity to it.

When the relay is factory reset it broadcasts the Shelly SSID. Connecting to it, I am able to start the process of cloud connecting it via the new "Shelly Smart Control" app. However, at the "Connecting to Wifi" stage, it throws an error and never appears in the cloud app. It then stops broadcasting the SSID and joins the network it was directed to join, but never connects to cloud. I re-attempted this with data disabled on my phone, but encountered the same problem.

While on the wi-fi network, every 30 seconds it loads the same message in the debug log:

708219238 cloud_aes.c:256         Connect to cloud: -8
708224299 cloud_aes.c:432         Cloud connection 0x3fff1a3c closed
708229409 cloud_aes.c:139         Reconnect after 30000

It never progresses past this point. Our firewall and network ACL's have been set to permit any traffic from this device, and yet we still receive these errors.

I have attempted to disable cloud connection from the Web UI and re-enable via the Smart Control app, but I still encounter the same issue.

I have factory reset and re-attempted setup multiple times, but I still encounter the same issue.

I have updated the firmware on this device, factory reset, and re-attempted setup, but I still encounter the same issue.

I have even attempted this with multiple wi-fi networks and on multiple phones and still encounter the same issues.

Please advise.

I would really appreciate any support on this matter.