A nice simple fix from SYSADMIN:
sudo rm -f /usr/lib/unifi/bin/mongod
sudo nano /usr/lib/unifi/bin/mongod
Paste the following in the mongod file:
#!/bin/bash
exec /usr/bin/mongod ${*//--nohttpinterface/}
Save the file and add permissions with the following command:
sudo chmod +x /usr/lib/unifi/bin/mongod