Wifi phone automatically switch problem?

RouterOS Beginner Basics
1

My phone is i9300, there are two devices, one is the main route rb951g-2hnd other is rb951-2n, when two devices are connected to a wds state,
Phone can automatically switch the strongest wifi. But when the phone is connected rb951-2n, speed is greatly reduced.
Then I connect two devices directly together with a network cable, wifi useless wds, the phone will not automatically switch to the strongest wifi, how to set the phone will automatically switch wifi, in the case of useless wds.

2

Use same ssid and different channels.

3

The effect is not very good, and sometimes will automatically switch, and sometimes it does not.

4

Switching is done by client. Set more aggressive roaming on his wireless driver or force disconnect by ap when low signal. But I don’t recommend the second option.

5

Thanks reply, it seems there is no way to solve.