Lowering MTU on PS4 and remote device causes black screen

[TillMueller]

Environment

• OS/Distribution: Ubuntu 20.04.01 LTS
• Desktop Environment: Gnome on X
• Hardware: Intel Core i7-10510U CPU and its integrated graphics card:
  - Subsystem: Dell UHD Graphics [1028:0962]
  - Kernel driver in use: i915
• Exact Version or Commit Hash and Installation Method: v1.2.1 AppImage (https://github.com/thestr4ng3r/chiaki/releases/download/v1.2.1/Chiaki-v1.2.1-Linux-x86_64.AppImage)

Describe the bug
When setting both the PS4's and client's MTU to 1420, the stream only shows a black image after connecting. If the PS4's MTU is set higher (1500), the stream seems to work, but contains visual artifacts. The other way around (PC MTU 1500, PS4 MTU 1420) the stream works.

To Reproduce
Steps to reproduce the behavior:
(After registering successfully)

1. Set the PS4's MTU to 1420 and connect it to the network
2. Set the client PC's MTU to 1420 and connect it to the network
3. The PS4 is discovered normally, starting the stream opens the stream window which only shows a black screen. No error message is generated, even after several minutes

Expected behavior
The streaming window should show the stream from the PS4 instead of a black screen when using an MTU of 1420 on both the PS4 and the streaming client.

Log Files
both_devices_mtu_1420.log (does not work)
both_devices_mtu_1500.log (works)
ps4_mtu_1420_pc_mtu_1500.log (works)
ps4_mtu_1500_pc_mtu_1420.log (works with artifacts)
Leaving_stream_running_for_a_few_minutes.log (again, MTU 1420 on both devices, does not work)

Additional context
Interestingly, when only one of the devices has the lower MTU set, the stream works, although with visual artifacts if the PS4's MTU is higher than the PC's MTU (although mixing MTUs is not a good idea either way).
I have done mosts tests and generated the log files on Ubuntu, however, I tried using the Windows (Windows 10, 2004, GTX 1080Ti) and Android client (OnePlus 7T Pro) as well and both did not work when using only MTU 1420. On Android, when using the PSPlay app, the connection works fine with an MTU of 1420.
Having looked at the MTU Chiaki discovers, it seems a bit too large to me, but I might be misjudging that.
Thank you for taking a look at this issue, if there is any additional information I can provide to aid in solving it, I will gladly do so.

Thanks again,
Till