This is insane. I had the same problem, and after reading this I deleted "ExpressVPN" on my mac, and my speeds went from 100 Mbps to 400+ Mbps! This is kind of ridiculous. There's no reason that an app that's not even running should be slowing down your internet so much. – oxeimon Sep 5 '19 at 20:39
Feb 25, 2016 Fix WiFi Connection Issues in MacBook and MacBook Pro Nov 17, 2018 How to Test Internet Connection Speed on Mac Apr 19, 2020
Nov 28, 2016
How to Fix a Mac with WiFi Problems and Dropping Connection Here’s a possible solution: Go to the “Apple menu -> System Preferences -> Network”. In the left-hand pane, click Wi-Fi, then “Advanced” in the bottom right corner. On the next screen, select every network in the list using Command + A, and use the “-” icon to remove them all. Solved: MacBook connects to Wi-Fi but has no Internet
Jan 10, 2020
For many Mac users, a slow Internet connection is synonymous with a slow computer. That’s because almost everything they do—from surfing the Web to checking email—requires Internet access. 3 Ways to Connect to the Internet - wikiHow Dec 04, 2019