Defender - False Blacklist Report

On a site I help maintain - maplewoodhobby.com - Defender is showing that the site is blacklisted by Google, both on the Defender dashboard in WordPress and in the Hub and wpmudev. (screen shots attached).


However, the site is accessible and comes up in Google search.
According to bannedcheck.com, the site is NOT blocked. (screen shot attached)

Based on other similar earlier error reports, I've have disabled and re-enabled the blacklist check, AND de-installed and re-installed Defender with no change in the blacklist check behaviour.

Why is Defender showing this false positive?
How do I fix this issue?

Thanks

John H.