Google has confirmed it is dealing with two separate issues with its search, one impacting mobile indexing and the other canonicalization.
Around September 23, website operators began noticing a change in how sites were being ranked by Google. Originally this was chalked up to a search engine algorithm.
Google has acknowledged both issues. In the case of the mobile indexing bug, it can result in no page being indexed. The canonicalization could result in a page not being indexed, or the wrong URL being associated with a page.
Google is working to resolve the issues as quickly as possible. Site owners will not need to do anything, simply wait for Google to fix the issue.
We are currently working to resolve two separate indexing issues that have impacted some URLs. One is with mobile-indexing. The other is with canonicalization, how we detect and handle duplicate content. In either case, pages might not be indexed….— Google SearchLiaison (@searchliaison) October 1, 2020
There’s no action to take with these issues on the part of site owners. We apologize for the issues here and are working rapidly to resolve them. We’ll update this thread as each is corrected.— Google SearchLiaison (@searchliaison) October 1, 2020