MacBook keeps switching between my 2.4Ghz and 5Ghz wifi networks for no reason I have my router setup with 2 frequencies:

When I'm near the router, I'm connected to the 5Ghz wifi network. 

But when I go into my bedroom, I am switching to the 2.4Ghz network because the 5Ghz signal is too weak at that distance (barely getting any speed).

So I manually switch to the 2.4Ghz, but my MacBook automatically changes back to the 5Ghz network. I switch back to 2.4Ghz, it stays connected for 2-3min and then goes 5Ghz for no freaking reason. 

I already placed the 2.4Ghz network at the top of the preference list in the advanced network settings, but it didn't help.

Running OS 10.11.5. Any ideas?
Try this...

System Preferences > Network > Wi-Fi > Advanced

Drag the various wifi logins to the order you want.  In your case, the 2.4GHz above the 5GHz.