@AndreasSwe I have tried to be patient while waiting for more help from TP-Link with this problem since I have had good experiences with their products over Linksys or D-Link in the past, but it...

@Daveomania Hello to anyone still following this thread - I found another thread describing the same issues with a Deco M9 and a temporary solution which has been working for me. In my Deco App, I...

In AP mode with IPv6 disabled on my PC, I am seeing no latency spikes at all. In router mode, with IPv6 disabled on both my PC and the Decos it still spikes every 10s over 3000ms. So no change there....

I think either IPv6 needs to be disabled on all devices, OR on the parent router/modem because it seems the Decos have trouble communicating when IPv6 is enabled on any device. I don't think...

Disabling IPv6 on my machine fixes the latency issue, but disabling IPv6 on the decos using the app doesn't change anything. The constant high latency every 10s still occurs, sadly.

I will swap my deco back to router mode and see if I can disable IPv6. This would be awesome if it fixes the issue.