I’m putting these in the same report because they have a similar cause (I think). It seems that Comodo Firewall has a problem honouring aliases for commonly used items.
See in the screen shot two identical application rules to allow inbound connections on MySQL 3306, when using the port set traffic is blocked (and I get a popup). When the port is defined in the rule alone it works.
In the same way when I specify a host in the source it is blocked, and when I put the host’s root IP it is not.
Edit: It seems setting the source port to any makes the difference (the one other difference in the rules pictured here). I’m guessing my web server uses a non standard outbound port for MySQL.
Still having issues with the Host Name though.