Stuttering playback without Transcoding TrueNAS > ATV

[vidkun 10]

I have a brand new TrueNAS build running Emby server that I'm having issues with playback stuttering even though it's Direct Play and no transcoding. Initially, I thought it was limited to files with high bitrates similar the guy reporting in the thread below. Was even seeing ffmpeg pegging a core at 100% despite reports of no transcoding.

 

However, my kids just had the issue this morning with a much lower bitrate movie. This time CPU usage is minimal. TrueNAS UI reporting 3% utilization and top showing nearly nothing going on.

So now I'm even more confused. I've been using Plex then Jellyfin for the longest time but trying to migrate to Emby so that I can get the family off of Plex. This is not helping the move though. 

So detail dump...

Brand new TrueNAS build:
Intel Core Ultra 7 265k
Asus Pro WS W880-ACE SE
64GB ECC RAM
Media pool is a single, 10 drive RAIDZ2 with a 1TB NVME L2ARC

Emby transcode and cache dirs are on a separate dedicated 1TB NVME drive

Emby runs in a docker container with the media directories directly mounted to the container as volumes (no SMB or NFS mounts). 

The NAS has dual 10GbE NICs in a LACP LAGG on Unifi Pro XG 10 POE switch. 

Client is official Emby app on AppleTV 4k over WiFi 5 5GHz via Unifi U6 LR AP. Client and server are on same VLAN.

Logs attached below. Any ideas where to start troubleshooting this further? Or any ideas what could be the issue here?

hardware_detection-63910745576.txt embyserver.txt