Yesterday, for some reason, the Google Search Console AMP (Accelerated Mobile Pages) report under the Search Appearance section, shows a huge spike in both indexed pages and errors. The next day, the report dropped back down to normal compared to the rest of the time frame.
Here is a screen shot from one of my sites:
The spike reached over 15,000 indexed AMP URLs and 143 errors, which was about double the average for the rest of the time frame in this report.
Many folks yesterday reported the issue on Twitter with the same result.
Anyone seeing their #amp page index skyrocket today? #seo @GregGifford @rustybrick @AMPhtml pic.twitter.com/3F6jSFJbKN
— Eugene Feygin (@rawseo) March 2, 2017
Google has not commented yet on the issue but it must have been a weird reporting glitch that double counted the data on March 1, 2017.
Update from John Mueller of Google:
@rustybrick @rawseo @GregGifford @AMPhtml This display-issue should be resolved now. Thanks for flagging!
— John ☆.o(≧▽≦)o.☆ (@JohnMu) March 6, 2017
