Hi - I have a new MBA - has High Sierra - I use an AirPort Extreme for my router - and it is less than a year old. My complex just upgraded the internet a few weeks ago - we are supposed to get 70-90 MBPS - I noticed my speeds were slow - checked and they were only in the 20's. I finally got them to fix their end - and now on my iPad I get 80+ - just checked and got in the 70's on my iPhone too - but my MBA and my son's windows laptop - are only getting in the 30's - I can't figure out why. If anyone has any ideas/suggestions - please let me know!