Hi and welcome to the community, you may apply standard troubleshooting process by Log out, update your game application switch off and on your device and login.
I have the same problem. At first they said i have 5 lives but when i went to collect they only gave one by one and now i can only send life to others but i am not getting any lives in return. Starting to wonder if they will remove this game too.
I did this over and over and i am still not getting lives but still can send lives. This is getting ridiculous and wonder if this game will be no more.