Please refer to your original post above for a moderator edit. If you are not affected by this particular issue, I have added a note in there.
Maybe take a look at Important note about Chrome and Firefox Local Network Access
and do also compare the hosted web app with the local web app.
Do compare different Plex client types in general, in order to determine if the issue can be connected to a certain client type.
Ensure that you are not on an old server version between 1.41.7.x to 1.42.0.x
If there are still issues, please open your own forum thread.
There has been a new Plex app version on the Roku platform last week. From now on, the new rules regarding remote connections are enforced there as well. just like the other Plex client platforms. Here is a detailed account what these changes entail: https://www.plex.tv/blog/important-2025-plex-updates/
As a result, it is now much more consequential whether your server is only accessible in a different logical network, or in public IP address ranges. See Client says it won't play from "remote server", although the server is local for a list of things to check.
