Google offered an update on the ongoing indexing problems, stating that mobile indexing and canonicalization issues are almost fixed.
An clarification about Google’s long running mobile indexing problems was tweeted by Google SearchLiaison. He claimed that 99 percent fixed is the key indexing issue. The canonical indexing problem, however, is still partially broken, with only 55% of it fixed.
Mobile indexing issue
The initial problem that publishers noticed was web pages dropping from the index, with many noticing it happening to website home pages:
This was happening to more than just the home page though. Another symptom of the indexing problem was that new web pages were taking a long time to get indexed and appear in Google’s index.
Some web publishers reported here and there that a partial fix was to resubmit dropped URLs to Google Search Console, whereupon the dropped URLs would be restored.