The OTHER thing that could cause stuttering is if it needs to be transcoding and that transcode is happening slower than realtime (unlikely to be happening here).

You’d look in the logs for a transcode log for this sort of thing:

frame=  408 fps= 82 q=37.0 size=N/A time=00:00:15.51 bitrate=N/A speed= 3.1x  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c875.mp4' for writing  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c876.mp4' for writing  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c877.mp4' for writing  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c878.mp4' for writing  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c879.mp4' for writing  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c8710.mp4' for writing  
frame=  796 fps=145 q=30.0 size=N/A time=00:00:31.65 bitrate=N/A speed=5.75x  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c8711.mp4' for writing  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c8712.mp4' for writing  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c8713.mp4' for writing  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c8714.mp4' for writing  
[hls @ 0x5c9ae0dde940] Opening '/config/transcoding-temp/transcodes/2d181c04b2b6d7ab2bdc2405c6ae5c8715.mp4' for writing  
frame= 1189 fps=198 q=20.0 size=N/A time=00:00:48.04 bitrate=N/A speed=8.01x

if the speed drops below 1.0x, you’ll stutter.

Honestly sounds like a job for a Raspberry Pi Zero.
Small battery pack and a USB key, a bit of software setup, off you go.

Install Raspbian: https://www.raspberrypi.com/documentation/computers/getting-started.html#raspberry-pi-imager

Set it up as a hotspot:
https://www.raspberrypi.com/documentation/computers/configuration.html#enable-hotspot

Configure Samba share:
https://www.raspberrypi.com/documentation/computers/remote-access.html#samba

Not a fix to a known issue, but sometimes cache problems can cause this, so it’s worth clearing the storage and cache on the android app.

After you log in again and can reproduce the problem, then a bug report is in order :-)

Jellyfin Server 10.10.3
General Changes

• Exclude file system based library playlists from migration [PR #13059], by @Shadowghost  
  

• Downgrade minimum sdk version [PR #13063], by @crobibero  
  

Jellyfin Web 10.10.3
General Changes

• Backport translations for 10.10.3 [PR #6326], by @thornbill