Stutter, Fps drop

[TheDreadPirate]

Unchecking the codec boxes only means you aren't using any GPU acceleration for decoding or encoding. If you check them that doesn't mean Jellyfin will ALWAYS transcode. Transcoding only happens when it is needed. That can be codec compatibility, container compatibility, subtitle compatibility, the network speed doesn't support the bit rate of the video.

On your shield, do you have the max bit rate set to auto? If so, try switching it to 100Mbps+.

Also, WiFi 5 on the 5Ghz band should be much more than fast enough for this video if you want to stop using your USB to ethernet adapter.