Photos just stopped offering WhatsApp as an option for sharing photos

I am used to taking photos with my iPhone, then selecting them in the Apple Photos app, and sharing them by sending them to somebody via WhatsApp. Until today. As of today, when I select a picture in the Photos app, and tap the share icon, it opens with a list of apps by which to share the picture, and WhatsApp has disappeared from the list. Not only from from the first options offered, but also from the "more" menu. I checked the permissions and WhatsApp has the permission to access all of my photos.

How can I fix this?

Thank you,

Peter