Posted in the M5 topic, but I have the same issue with my M9 Plus v2 ... very frustrating! https://community.tp-link.com/en/home/forum/topic/171562?replyId=561712

So I have an M9plus and 2x M5s covering my house. Internet surfing and streaming seem to be fine, but online gaming is a nightmare, with ping spikes up to 999ms making it basically unplayable. I've...