I had my tumblr Cloudflare-enabled, when without warning it got dropped as non-valid. This had the effect of dropping the url of tumblr.mydomain.com right off

I had my tumblr Cloudflare-enabled, when without warning it got dropped as non-valid. This had the effect of dropping the url of tumblr.mydomain.com right off of Google's index. After some WTH moments, I ended up having to use the regular IP provided by Tumblr to get things back to normal. I was not happy with things changing without warning but it's a free service so I guess it's YMMV.