RT-AX88U QOS not working anymore

[Gravityz]

I recently tested bufferbloat performance again on my RT-AX88U
normally it was very good(A+ 0ms increase) but now latency is all over the place.
last year my internet increased to 400/40 Mbit. i suspect that this speed is to fast for cake to handle
i have also read about disabling HW flow cache with this command

1. nvram set fc_disable_force=1

what are the max speeds suposed to work with Cake?
do i need to disable the flow cache?

i also tested other QOS settings like traditional, adaptive and even FlexQOS but nothing seems to work anymore

 

[Tech9]

what are the max speeds suposed to work with Cake?

Around 300Mbps on your model router. And please, don't waste your time with Waveform.

 

[Gravityz]

ok thanks. i will cap my max speed then.
better stable connection. 300mbit is more than enough.

 

[Tech9]

Your connection stability has nothing to do with online tests evaluating the issue they create in first place. Below line saturation speeds you have no bufferbloat. You can test with simple bandwidth limiter and the "score" will be about the same. There is a chance you are only hurting yourself with this QoS.