Widget only displaying 2 items

did you read this?

https://www.wprssimporter.com/faqs/1300/

Yep – read all the FAQs. It’s set to 5 and 5, and I’m still only getting 2. But I’m not autoposting my feeds. I’m just displaying them in the widget and that’s where I’m having the problem.

I ran into the same problem and was able to resolve it using the maxperpage shortcode parameter. I used it on a page and not a widget but this might work there too.