When your port is blocked, there’s a firewall blocking it. That’s what firewalls do, and nothing else does that.
It therefore means that you have a firewall, some firewall, possibly one you don’t know about, blocking that port. You must find it and configure it to allow incoming traffic on your chosen listen port.
It might be the built-in firmware firewall on your router, improperly configured. It might be one or more software firewalls you have running, quite possibly installed unknowing. It might be a firewall further upstream from your connection, which you might or might not be able to do anything about.
Ultimately, it has to be up to you to find the firewall.
Don’t ever connect to the internet without one known working firewall. Never, never, never. Windows has a perfectly good firewall built in to it, so make sure that one, at least, is up and running whatever else you do. Bitcomet can, if so set, manage that firewall itself, opening the port that it needs.
There are many 3rd party software firewalls. I discommend using any of them until you have garnered considerable expertise in what you’re doing – and they mostly put the burden of configuration on the least-qualified person (you) anyway, so if anything gets through, they can say it’s all your fault. Who needs that?
Having more than one firewall does not make you safer. It gives you headaches. Everything you do to configure one firewall, you also have to do to all the other firewalls. Firewalls are like gates, and it only takes one closed gate to block the path, whether the other gates are open or not. You can spend a lot of time fiddling with one of them, when the problem is that another is closed.