Low speeds with SQM on GL.iNet sft1200 Opal

Hi everyone,

I recently set up a GL.iNet SFT1200AC “Opal” as my main router, cascaded with three Deco X20 (AX1800) units running in Access Point mode.

My goal was to reduce bufferbloat, since I was having issues with streaming and social media lag.

My ISP provides an FWA connection rated at 100/30 Mbps, though I usually get around 200/40 Mbps during the day and 150/25 Mbps in the evening.

After enabling SQM (CAKE + piece_of_cake.qos), speeds dropped dramatically: I can’t get more than ~65 Mbps down and ~20 Mbps up, even when setting generous bandwidth limits.

I’ve tried link layer adaptation 44 bytes (and 34 bytes) without noticeable difference.

Am I missing something in the configuration, or is the GL SFT1200 simply too weak to handle CAKE at higher speeds?

Thanks in advance for any insights or shared experiences!