Multiple wifi sources connection issues

[mshoward82]

I am having issues with my wifi staying connected.

I have a two story house with concrete walls. So I have my main wifi(from the router/modem) upstairs. Then I have a second wifi extender downstairs.

Now there is still a small signal from the other wifi signal when either upstairs or downstairs. This is where my phone Xperia XZ1 Compact runs into issues. It seems like it is constantly struggling to decided which network to connect to.

My phone is constantly dropping wifi signal and can't decide which signal to stay connected to. Making browsing the internet a dificult task and even ends up using cell phone network instead of the wifi.

If I tell the phone to forget one of the networks, it has no problem staying connected to the other.

None of my other devices in the house have any issue staying connected to one of the wifi devices.

Any help on how to make my smartphone smart enough to pick the strongest signal and stay connected?

[XL]

Turn the network rating provider from google to none. This method work for me.

Wifi/wifi preferences/advance/network rating provider 

[Kevinod]

I have had this problem since January. Sony have not bothered to fix the problem. Phone is basically useless and always have to use mobile data. Sony phones are pathetic. 

[SenXEK]

I've similar wifi setup at my house, main wifi router downstairs and wifi range extender upstairs.  I don't have any connection issue at all except that it'll take a moment for the connection to stabelize, usually in less than a minute.

Does relocating the extender to another place help?