google does not respect the CANONICAL tag?

Hi

This is a valid page of my site:
learn-greek-online.com/ask-greek/1115/difference-between-thes-and-thes

When I check google index for variations of the page, It shows 3-4 results:
site:learn-greek-online.com/ask-greek/1115/difference-between-thes-and-thes?show=1119

All of them have the proper canonical tag, which tells google to index the proper page (mentioned above).

So why google does not respect the canonical tag?

In Google Search Console, under "Indexed, not submitted in sitemap" I see such pages and I want to get rid of them.