Ok so, if you type in a channel: irc://someserver:+6697/help

and you double-click,

It tries to connect to port 6667 no matter what port you specify.

Thanks for your bug report. I just tested this on the Freenode link here, which uses the same format as your example, and it worked correctly. Do you see the Link request dialog pop up? In my Link request, it states the correct server address, port, and channel name.

I see the link request.. It seems to be that whatever the active network and port you are on uses, it uses this.

It would be nice to have it use the currrent port in the link!

When I test this on the link mentioned in my previous post, it uses the port in the link, which in this case is +6697. This is different from my active server port, which is 6667.

Can you please confirm: in the link request dialog, under "mIRC has been asked to connect to:", I see "irc.freenode.net:+6697 #mIRC". What do you see in your link request in this location?

https://www.dropbox.com/s/o1i805uutloqob7/Screenshot%202020-03-15%2003.00.51.png?dl=0

Right, so this is only not working if you type the link into a channel and double-click on it?

If you click on the Freenode link in your web browser on this page does it work?

Yes.
And yes, clicking on an irc:// link from a website DOES work right.

Thanks for clarifying. This behaviour is intentional. You can find my replies to a similar discussion here.