A very common question I see SEOs and publishers ask is that they see that Google Search Console shows them in position 3 for a query but when they look at the actual search results page, they are not in that position. Or similar related questions that what they see in the actual search results does not match what they see in the performance report in Search Console.
Like I said, it is a very common question and the response is very common too. In short, what you might see in the Google search results, the next person might not see. It can be around geo-specific changes, it can be around personalization or even data center fluctuations.
In addition, to make things worse - it might be that you are in that top position and getting a ton of impressions but you just don't see it. Meaning, you are maybe an image in a featured snippet and Google is counting those impressions but you don't think to look at the images in the featured snippet, you just look at the search results.
John Mueller of Google was asked about this on Reddit and said:
Usually that's personalization & local targeting. Often you can guess if the queries are expected to have a large amount of impressions, and if your site is listed as being in the higher positions, but it just gets very few impressions. You also see this when you drill in by date and see that it's just getting very few impressions sporadically (rather than regularly).Another option is from images. Some queries sometimes show image one-boxes (where you have a bunch of images towards the top of the results), and if an image from your pages is shown there, you'd see that as an impression in Search Console (similarly if the image is shown in the knowledge panel part on the side). I suspect not a lot of these images get clicks, so it can appear that you have a large number of impressions, a high position, but few clicks for those queries. When trying these out, make sure to drill down in the report to the appropriate country version, and use the appropriate advanced search setting for that country, so that you're as close to what users see as you can.
So you probably can trust the Search Console performance report, you just need to learn how to filter the report and dive into how to see the search results page as the performance report reports on it.
Forum discussion at Reddit.