Google says I have Poor URL's on my site... how do I fix

Site URL: https://www.walkingforhealthandfitness.com

In Goolge Search Console I get this error message on a graph: 48 poor URLs.

This began 3/30. I had no idea until I typed my website address into Google Search and a blogpost from the site appeared but not the home page.

What is the problem?

How do I fix it

See attachment...Notice the problem doesn't appear in mobile. 

Thanks,

Frank

I have the same question.  In the middle of September 2020 google started ranking almost all our pages on mobile as "Poor URLs". Should this be of concern? Is there anything to do to turn them into "Good URLs"?

This problem might have caused either by images on your website, or tag links , plugin which cause the site loading imbalance. google see that as poor url. 

Try to compress or zip files, also optimize your images, etc. In that case, you will not have shifting on mobile and on desktop as well.