Imported Image Size Problems

I’ve set up a few feeds and for some when they create the post (Feed-to-post) the image used as the feature image is displayed much, much smaller than its actual size on the original post from which it has been grabbed.

If this is not the case then it shows instead a very small version of the site logo from which it is feeding instead of the image from the content of the post? This is the same for a few different feed sources.

How do I have it grab the full size image and use it as the feature image without resizing it too small?

Thanks.

https://ww.wp.xz.cn/plugins/wp-rss-aggregator/