Casting local file vs plex

Hi everyone. I’m new to iOS and Infuse but have been a Plex user for a long while now. My conundrum is that upon downloading some files into Infuse (from my plex server), I’m unable to cast these locally stored files to an Android TV box.

Don’t get me wrong, casting does work. It’s just that whenever I do this, I can check on my plex server and I see confirmation that it’s casting it from there and not the locally stored device on my iPad. I also experience sever buffering when this is happening on a slow internet connection.

I know it’s possible to cast the file as I’ve tried turning off my Plex server and the casting worked fine with no buffering whatsoever.

It’s not a solution for me to turn off my Plex server when I want to do this. Perhaps there’s a way I get to specify which specific file gets casted? Or is there a setting that sets this sort of playback to prefer the local file and not the one in my plex server (in another network)? I’ve probably overlooked something so obvious but I can’t seem to figure it out.

Your help is greatly appreciated.