So I'm new with this Deco M9 Plus that I just installed and set up---- so far I really like it but I am confused because I can walk around my 4,000 ft² house on both floors and my phone will never switch, even if my phone is closest (even next to) to a different deco unit that it is currently connected to.

I thought the whole purpose of this mesh technology was seamless transition from one unit to the next for the best performance and Wi-Fi integrity of your devices????

Tech support was once again useless they told me to move the slave units closer to the main unit but then when I questioned their advertisement that this system is meant for a 6,500 square foot home they stopped helping me.