Unwanted picture scaling

This plugin is scaling down pictures uploaded as category picture and as a result, when displaying the grid with pictures their quality is very bad. I need to display 600x600px pictures, but the plugin is scaling them to 300×300 and then resizing to match responsive layout of the page.
How can I remove this scaling?
Example: uploaded picture url: https://sitename/wp-content/uploads/2020/04/spodnie-600x600px.jpg
The same picture url when inspected on the website: https://sitename/wp-content/uploads/2020/04/spodnie-600x600px-300×300.jpg (“-300×300” is added).

• This topic was modified 4 years, 11 months ago by olekn.