I had a 2009 Android phone and my Mac Mini could 'see' its hotspot but the signal was unusably poor. I bought a 'TP-Link' from Amazon and this worked. (It costs about €25,it's usb powered and the size of 20 cigarettes. It's a wifi bridge and/or repeater and it has an ethernet connection can be made into an input or an output port.)
I bought an new Android last week and it works just fine without the TP-Link.
Hope this helps,