Only show posts for current category – category and article pages

I tried to post this to the author’s support site, but I’m not getting a registration email to be able to post and I’d like to move this along…

I’d like to filter category posts displayed only for current category (for category and article pages). Seems like it would be relatively trivial, but I can’t figure out how to modify the SQL in the plugin’s functions.php to do this.

Any idea how I’d modify the plugin to filter display by active category, but leave it ‘general’ for pages like the homepage?

Thanks in advance.

https://wordpress.org/plugins/popular-widget/