Unable to share purchases with family.

I am the organizer of a "family" and want to share apps with a family member.

I have enabled "Purchase Sharing" on my device (Settings → Family → Purchase Sharing) as well as on the other device.

When I browse an app, that I purchased on my phone, in App Store, I see that I can download

or open it.

However when the other person in my family is browsing, App Store requests them to purchase the app.

I send the link directly from App Store so the SKU are supposed to be the same.

What could be the reason for this?

I have iPhone 13 (Chinese spec) and they have iPhone 15. Both fully updated to the latest iOS.

I am also paying for iCluod+ and Apple Music and have no problem sharing this with the other acoount.