Google Search Console’s Search Analytics Report is still showing some clicks to HTTP version of site even after migrating to HTTPS. HTTP should show 0 clicks. Why is it? Hard to imagine even after moving this site to HTTPS three and a half years back, still showing some Search Analytics Data.
Answering to this anomaly, Google’s John Muller sees these clicks as normal because some queries can still trigger the HTTP version even if the canonical version has been set to HTTPS. Going further, he also added that these can happen in individual cases. At times, you can observe it by finding the queries that trigger it, even if an https url is canonical.
See the forum discussion at Twitter.