Sharing Minecraft App with other devices.

Hi. I bought Minecraft App on my sons iPad using his apple ID. It states purchased by my son but downloaded by my husband. Our family sharing is set up using my husband's ID. We don't seem to be able to share the app on other devices even though it states it can be shared on the product info. Can anyone help me figure out why? Normally the cloud symbol shows up when something has been purchased previously but in this case it's asking us to purchase again. Any assistance appreciated. 😕