In the default site pages library I have site pages with a banner image uploaded, tried everything, from the site or locally, and as you can see from the image below, the image is just a broken link that when clicked it gives me the err_invalid_response.
For the default Home.aspx , the banner image is in /sites/layout.../sitepagesthumbanil.png
While any page I create and then upload a banner, the image is in /sites/getpreview.ashx?path...
It's like it doesn't find the image?
Ultimately, what I need this image preview is because I'm using powerapps to display the articles in a gallery, and for the image whenever I use ThisItem.BannerImageUrl or ThisItem.Thumbnail.Large , a white images gets displayed, so I'm open to other ways to display the image of site page.