Hey all, I'm very new to self-hosting and have no background in anything computer-related. I'll explain in as much detail as I can. I'm running Plex on a Synology DS220+. I'm using the Plex app, i.e. not using Docker (see note below).

The issue: I can watch Plex on my local network in 4K, but outside my local network it barely makes it to 720p. I thought it was an issue with my upload speed, but I got gigabit last week and it hasn't fixed the issue. I have remote access enabled in Plex through a manually-specified port. The issue persists with my own account and any friends who have access to my library.

I appreciate any advice, links or questions you can offer!

NOTE: I understand the benefits of Docker and I promise to transition in the future. I spent many hours learning and troubleshooting, and it was even functional at times, but eventually I needed something that just worked.

EDIT: You all have been so helpful and supportive. Thanks for meeting me where I'm at and sharing some potential issues.

EDIT2: I found the culprit by accident. I had UPnP enabled on my router. I turned it off and my local speeds increased significantly, and my Plex library is available remotely. I don't know how or why UPnP is related, but that's what the solution was for me. Thanks again for all your input and support.