My loved one couldn't see or hear me

Anytime you encounter an issue like this, it's important to make sure that you are near strong wifi, and not outside or on weak cellular data. 

If the problem still exists on strong wifi, then you and your loved one should both try leaving and rejoining the call to see if the issue fixes itself. Leaving the call will not end the call and you can always rejoin without any issues. 

Finally, please make sure that your microphone works. If you are using earbuds with a microphone on it, please make sure that it is not damaged.