If you opened your firewall port 8090 and still cannot be reached from the outside: Maybe this is the reason.
I installed ipFire as a new firewall, opened 8090, and ran into this problem, until I found this article:
https://forum.ipfire.org/viewtopic.php?t=7090#p47551
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So the first thing you need to do is goto your router configuration page and click the ipfire tab. In that list select and install miniupnpd . Thankfully IPFire takes care of the annoying bit of getting it to boot with the firewall, so the next step is one simple line and you will be done!
Connect to your machine via whichever method you like, I used SSH.
Then change directory to /etc/sysconfig/ , after doing that run your favorite text editor (I choose VI) and open the file rc.local .
At the end of the file paste this line,
iptables -I FORWARD 15 -j UPNPFW
The command states that you are INSERTING in the FORWARD chain, the UPNPFW entry. The number is the position and I simply chose it to be around the other tables like PORTFWACCESS but after all the special DROPs and before the final DROP. You’re free to change the number but I can’t guarantee that it will continue to function fully.