OAuth error when adding to Google Home

I’ve got a new Samsung TV. I’ve created a SmartThings account, which I’m logged into on both the TV and on the Android app on my phone.

I’m trying to add the TV to Google Home (so that I can bypass the SmartThings app and control the TV through the Google Home app).

Google Home has recognised something related to SmartThings - as a result of either to the TV being connected to Wifi, or my having the SmartThings app installed on my phone. (I know this because, when I head to Google Home, there is now a suggested “Connect SmartThings” option.)

However, I’m unable to complete the OAuth when I click that option. I’m asked to “Authorize” twice. The error message at the end only appears very briefly - I’ve had to try adding it via the manual route (Add device > choosing SmartThings from the list) in order to get the error message to stay long enough to screenshot it!

Does anybody have any suggestions? Thanks in advance!

I’m a new user so limited to one image per post; here’s the full flow: