Mesh network clients constantly connect to wrong access point

[Orcrist]

I have a network setup with an RT2600AC as my router, and two MR2200AC units as access points with wired backhaul - both placed probably 50-60 feet from the router. I have three primary networks: Homewifi, guest, and an IoT network that is 2.6 only. I have observed that my devices on the IoT network are constantly unavailable despite all having an AP in reasonable proximity. For example, I have a cluster of devices in my living room that sit no more than 10 feet from an MR2200 AP (some are less than a foot away) and instead connect to the base unit across the house and through rock. When I look in the router I see the connection and a tiny signal. This network has been set up for months so surely it could have optimized itself by now. How can I fix this? Most of what I read says the clients decide but they are clearly making dumb decisions. Can I set up a network to be accessible only on certain access points? I am getting really frustrated and the only solution I can think of is to set the three units up as independent WIFI networks - which would stink because then I would not have a seamless WIFI network for regular clients to use anywhere in the house

 

[godnorazi]

Try disabling IPv6 in Local Network

 

[soberego]

Hi, I have a similar issue.
Would you recommend disabling the IPv6 where exactly ?
The devices that keep on connecting to the most remote AP are IoTs (printer, etc), not sure how I can do that.

Kind regards

 

[EAZ1964]

Many IOT with fixed position in house seem to struggle to connect to the nearest AP.

I solved it by installing a single 2.4Ghz only AP (cheap TP link in my case) on a separate wifi SSID on a central location (no mesh). This next to my 5ghz Mesh network for other use.
The issues were solved instantly.