I’ve been a MacBook Pro user for close to fourteen years now, both at home and at work. At home, I write my many books and conduct supporting research on my personal MacBook Pro.
Since I’m an infosec professional, I’m aware of threats to MacOS and associated components, so I run several security tools, among them Cylance, Malwarebytes, and Sophos. I use privacy-centric browsers and search tools.
Starting yesterday morning, my browser (Brave) started acting up quite badly: new pages simply would not load, and the browser would throw nonresponsive page errors left and right. I also use Firefox, which continued to function normally, Safari too, so I was pretty sure the problem was with Brave itself.
I cleared all cache and cookies, tried building a different profile in Brave, and even removed and reinstalled Brave. No go. I posted an entry in the Brave Community in the hopes that someone else would recognize my problem in case I could not fix it. I am somewhat tied to Chromium-based browsers, but prefer not to use Google Chrome. SRware Iron is an alternative, but they don’t update it frequently enough for my needs.
Since other browsers were working normally, I could dismiss my Internet connection, my local network, and DNS as possible culprits.
Next, I turned to my security tools. I had noticed that Cylance had been using about 90% of a CPU core for a few days, so that was my first object of study. I shut down Cylance, and immediately my Brave browser problem was solved. I turned Cylance back on, and the problem returned. Gotcha!
I removed and reinstalled Cylance, hoping that this would solve the problem. That was a few hours ago, and Brave is happy as a pig.
Retrospective: I cannot imagine ordinary consumers going through troubleshooting like this. My decades of daily hands-on software / network / systems / OS / security engineering on Unix and other OS’s helped me zero in on this fairly quickly. I shudder to think that most consumers just turn security tools off when things stop working, and go unprotected thereafter.