Why isn't Google Indexing Discourse? SEO concerns

[mstm]

This google behavior started months ago and sadly is getting worse.

Sudden drop in traffic

The decline continues in my two discourse sites, all previously indexed pages are becoming “Crawled - currently not indexed” and disappearing from Google search. [google] I can understand on one site but is it possible that it happens with in two completely different forums?

The sitemap in my case didn’t help …