On April 25, Google tweeted that it may have selected canonical URLs for some pages and that bread crumb trails on mobile could show the unrelated URLs.
In some rare instances, Google said that this could even prevent proper indexing.
The purpose of breadcrumbs is to show the position of a page in the hierarchy of the site and will appear under titles in the search results.
There wasn’t any actions offered up by Google for webmasters or SEOs to take in this situation. But if you think that your site could be affected, check out Google-selected canonical URL by heading to your Search Console and entering your page’s address into the URL Inspection tool.
If there is a better canonical URL than the one that appears, there are steps that you can follow on Google’s duplicate URL help page that will help you suggest a new one.
This is the fourth bug that Google has disclosed in April. The company is still resolving issues with Search Console reports, which has some SEOs frustrated over its general lack of reliability as of late.