Also check the easymesh feature on the AX53 main router is switched Off.

@noris_sasaran Hi, I had a similar problem with my X60 Deco in AP mode, my main router is an Archer C80, on the Deco app go to "advanced" and disable "smart DHCP". Worth a try.

@Kev205 Hi again, I can second you with this, the Deco app speed test on my M9 plus also under reports in a similar way, max speed I ever got in router mode (no double nat) connected directly to the...

I tested this on my C80 with my Deco's, disabling easymesh on the C80 router does resolve the issue.

@Ache Hi, have a look at this article. https://community.tp-link.com/en/home/forum/topic/697580

@Skydog Deco light can take a while to go green so yeah be patient lol. Cheers