I can use ports 25565 and 25566 to host minecraft servers but when I try to use port 25567, it does not allow me to connect to that specific port or any other port at all.

When I googled this issue I was brought to this bug https://bugs.mojang.com/browse/MC-35588 

It's similar but does not explain how it was fixed. I have ports 25565 running 1.7.10 and 25566 running 1.12.2. I would like to run another 1.7.10 but I can't find another port to use. 

I have it forwarded in my modem properly and I see it on my LAN but it does not allow me to connect to it.