Keep previous and next links within category.php

Hi all

I’ve set my site up so that there is an index.php page that shows the past 3 posts.

Then there is a news category page (using category.php) This shows a list of posts that are marked as “news”

The problem is that on the news page (category.php) the links to show the next and previous posts take you to the index.php rather than staying on Category.php

You can see this happening here:

https://www.loungetesting.co.uk/news/ – Try clicking on “next”

Any help would be much appreciated as I’m stumped!