Images from url showing in data editor but not in app

Hello everyone, I’m facing this problem: when I specify URLs for images that are hosted on my website, those images are displaying in the data editor but they don’t appear in the app.

This is the failing image URL:

The image should appear above the name, at the top, but it’s only showing in the “data” section, when I double click the profile_picture cell.
In the data editor as well, I can see the image only when I double click its cell.

Image URLs from some other domains seems to work fine.
This is the working image URL:

Note that the URLs I’m trying to use point to publicly available images as you can see.

What I’m doing wrong?
Thank you very much for your help!