when you play the game from a family library its a bit difficult but possible when you startup the game the first time it should work on the first startup you have to restart the game 2-3 times but the second time it wont work heres what i did:

1.copy or move your save file to another location 2.reinstall the game 3.login to ubisoft connect 4.move the save file back to the save location 5.restart the game 2-3 times 6.enjoy the game its annoying but the only way i could get it to work with family sharing if you close the game repeat the process

when i bought the game it everything worked for me if you dont want