Help me troubleshoot my ipv6 gateway death

[MartB]

Hey there, whenever i start an upstream speed test (LAN->WAN with 200 Mbit/s) my ipv6 upstream gateway just proceeds to stop passing packets and does not respond to pings anymore for some time, even after the load dropped to 0. How do i troubleshoot this?

I tried capturing packets but i did not find anything.
The ipv6 default gateway just stops replying, is anyone experiencing something similar with 20.7.4?
Could this be network interface related? (realtek)

Throw any cool troubleshooting commands at me that you have.

Edit:
After disabling my upstream FQ Codel Pipe the issue stopped.
Im currently trying to figure out if a specific rule is causing it.

Edit2: solved
I added Interface2 and fixed the directions on my rules and it now seems to work correctly, im a bit confused here, how can the traffic shaper cause these kind of issues?