Phoenix will not be able to receive payments when it is in the background, or when it is closed.
This happens because: Tor is enabled.
For security tor is enabled when “on-screen” for obvious security reasons
This is a security measure to protect your wallet. To resolve this, you can try the following:
Disable Tor: If you don't need the added security of Tor, you can disable it and see if that resolves the issue. To do this, go to your Phoenix wallet settings and look for the Tor option. Disable it and restart your wallet.