By default, Plex Media Server is configured with an non standard port (for security reasons) instead of 32400. This means that you may be limited to streaming video at a reduced quality of 2 Mbps. Fortunately, there is an easy fix for this issue.
First, go to your seedbox dashboard and open the Plex page. Then, hover over the link called “here” that takes you to the Plex Web UI:
When you see the link in your browser, take note of the number that appears after the colon after “xirvik.com”. This number is the port that Plex Media Server is running on.
Then, log into Plex by clicking that link. Open Settings using the button in the top right:
Go to the “Remote Access” section. Then, check the box that says “Manually specify public port”, and then enter the port that you got from the link earlier.
After you do that, the “Remote Access” section should have green text that says “Fully accessible outside your network”. This means that you will now be able to stream from Plex at full quality.