Help with Google Family Link parental controls

[goister]

Hi, I'm trying to install parental controls on my child's Note 8 and it's not working. Each time I go through the following screens

1. Android settings - Select "Google"
2. Google Settings - Select "Parental controls"
3. Set up parental controls - click "Get started"
4. Who will be using this device? Select "Child or teenager"
5. Next steps - Click "Next"

On the Note 8, it just hangs there with the progress spinner, and after a while, it shows "Something went wrong" and tells me to try again later. I also tested on a spare S6, and after step 5 it just goes back to step 2 after 1-2s. Finally, I also tested on a newer device (Samsung A12) and it's able to proceed to the next page, which is to select the child's Google account.

Both the Note 8 and S6 are running the latest firmware and have all apps updated to the latest versions. Any ideas what is wrong?