I'm seeing this too this morning! 😱 . I'm guessing it must be a bug - I can still access the GMB dash for all of my clients when I access via the SERP, just click on any of these to access the dashboard for that profile:
New advertising option:
A review of your product or service posted by a Sterling Sky employee. This will also be shared on the Sterling Sky & LSF Twitter accounts, our Facebook group, LinkedIn, and both newsletters.