Broken app icons in f-droid website

Recently noticed that a lot of apps on f-droid have the default f-droid logo. Apps including but not limited to nextcloud, Les Pas, New Pipe have this.

Is there any reason why these apps have this default/broken app icon?

Thanks

We have been several to notice that.
It’s always under investigation.
Yesterday I published my app (impacted by this bug) by adding an icon called (icon.png) in all locales of my fastlane structure.

ex:

fastlane/metadata/android/en-US/images/icon.png

We will see.