Roku Direct Play - Causes extreme lag on server connection

[JA64Flyers]

Server Version#: 1.19.4.2902
Player Version#: Various Roku
Internet connection (tested w/ Speedtest) 500mbps down / 45-50mbps up
Server upload speed set to 25 mbps, 8 max stream bitrate
Router: Ubiquiti Edgerouter 4 v2.0.8 - Smart Queue enabled

Hello all! I’ve been experiencing some intense lag over the past few months during some plex sessions. I have quite a few users on my server, up to 4-5 at one time. After a pile of testing, it seems to be related to Roku users and direct play. While using Direct Play, regardless of the bitrate of the file, it will murder my connection. This can occur even though it’s using less than half my upload. Whats strange to me is i’ve tested streaming a 17 mbps file (i took off anything that would cap the stream) to plex in a web browser on a remote PC, it used up most of the bandwidth allotted, and it didn’t give me a single high ping.

I have attached an example of how direct playing a 2 mbps file impacted my connection. The rest of the images show different files being streamed, some transcoded, some not, and what devices we tested. (roku user B didn’t effect my testing)

Any ideas as to where i can go from here? Thanks for your time!

plex issue.zip (4.5 MB)

[JA64Flyers]

Does anyone have any idea why plex is doing this or how to correct it? Short of disabling access to all my users, which defeats my purpose of the subscription.

[JA64Flyers]

Apparently its not limited to just Roku boxes or direct play, though that setup provides the highest ping spikes.

Edit : I’ve eliminated or replaced all other parts of my network, so i know it’s not another device messing with things or my switch. The strange thing is i can test a file over and over, reproducing the high pings. Then suddenly, i can’t recreate it anymore and everything works as expected.