My ISP speeds are 300/100Mbps DL/UL, I have Deco M9 Plus connected to the main router, I set Deco QoS to 200/50Mbps and PS5 directly connected to the main router which have the full speed 300/100Mbps, everything else is connected to Deco only, but I still got ping spike during online gaming even though Deco devices only reaching 200/50Mbps Max.

I heard SQM is better than QoS in this situation, now I have the regular switch TL-SG1005D and I want to upgrade to TL-SG108E managed, is there any better solution and affordable for less than $50?