QueryMonitor plugin (it is free) to the rescue! Among other debugging staff, QueryMonitor has a "Template" sub-menu when in front-end, which also displays the current template file in use.
Moreover, when you click the "Template" sub-menu, you get a lot more useful details:
1) The template file currently in use.
2) What template-parts that are being called from inside the used template (for more details, you can check the get_template_part() function).
3) The template hierarchy starting from the most specific and going to the most generic. e.g: Now we are using the
single.php template. But if we create the
single-post-what-template-should-i-change.php (what-template-should-i-change is the slug of the post I was currently watching) template file, then we can create a unique tempalte ONLY for that specific post.
Hope, that helps.
P.S: I'm not affiliated to the plugin whatsoever, just using it and it really helps!