Apple doesn’t support the in-app purchase shared within family members in Family share. (Refer to “https://support.apple.com/en-us/HT203046” )
One suggestion on solving this problem is:
- Login your other device under the same apple ID, you paid for the full version.
- Download the game ( if you have download before , please deleted it first. And download it under your apple ID)
- Enter the purchase screen in the game.
- Please choose “RESTORE” option.
Then you will have this full version game in the device without double pay for it.