Hello, My site was once entirely indexed and now it is getting deindexed by thousands every day and I can’t seem to pinpoint what my problem is. The google index is currently at 21k/71k urls indexed and bing index is at 14k/71k.
This is a tough one to diagnose without seeing more. Have you checked your Robots.txt? Any changed to your site, like the addition of a NoFollow? Are your sitemaps working properly? Any errors in Google Webmaster Tools, Bing Webmaster Tools or Yandex Webmaster Tools? Has your hosting been having errors? Best of luck!