NBK752 band steering problem

Frustration with where devices choose to connect is one of the most common discussions on the Community Forum.  I am not aware of any residential mesh WiFi system which provides a method to force devices to connect only to a specific access point. (Amazon eero, Asus, Google Mesh, Netgear Orbi, Linksys, TP-Link, etc.)

Many WiFi devices connect to the router and then change to a different access point when it comes on line. (My phone, for example, connects to an access point in the garage at 2.4G when I drive up.  After walking into the house, it reconnects at 5G inside the house to a different access point.)  If the device connects to the router and then never switches to a different access point, this is very frustrating for users.  Keeping the network on line with UPS power is the only practical solution.  No idea what would cause this LTE router to reboot. My cable modem Orbi router remains on line for months until the electric utility favors us with a power outage which totally drains the UPS.

Four WiFi access points in a single house may be enough that you could experiment with modifying Transmit Power Level.  There is an Advanced setting to change the Transmit Power Level for user facing WiFi to less than 100%.  It affects every access point, including the router.  (The backhaul WiFi link power is not affected.)  That room that currently has a strong signal where the iPad "flips" might be more consistent if the 5G power level was reduced.

Since adding the WiFi Extender appears to have 'solved' that room issue, messing around may not be productive.