No. Most likely explanation is that you have indeed no proper remote access.
There is Plex Relay, which can help in a pinch. However, it is limited to max. 2mbps bandwidth for Plex Pass holders.
That is usually plenty for music.
For video, although it is theoretically possible to reduce the bandwidth of a video to 2 mbps, but it requires
the ability of the server to perform video transcoding at all (ensure it is not disabled in the server settings)
the ability of the server to use hardware transcoding to the HEVC/(H.265) codec. https://support.plex.tv/articles/115002178853-using-hardware-accelerated-streaming/
(The default AVC/(H.264) is only able to achieve bad looking picture at only 2 mbps, thus you will need the more modern HEVC codec. However, old CPU/GPU chips don’t have support for this.)
The best way is to try and resolve the remote access issues.
This is solely down to the plex app. I can access the server from my phone’s chrome browser and play files. I can see the files in the app, but when I select a video file to play it says source error.
I’ve even tried setting up Tailscale service to get around this but still the problem persists.
When I look at the dashboard on my server and try to access the file from my phone, it shows that the phone connects and is trying to serve the video, but then disappears when the error message appears on my phone.