I've been using "Malwarebytes Browser Guard" for a couple of months, and I've noticed a few issues.

There's no doubt it does a great job blocking malicious sites, trackers, scams, etc. But it also slows down the browser when I have several tabs open or when loading more than one tab at the same time. After testing, I noticed a pattern (at least in my case): the more images a website has (Google Maps, ArtStation, Pinterest, etc.), the worse the browser's performance gets. So, I went into the extension's settings and disabled its three main features (Ads/Trackers = Off, Malware = Off, Scams = Off) for each of these sites, but to my surprise, it didn't work—the sites were still slow. I assume that Malwarebytes is still scanning all the links on the site, but the fact that this happens even after disabling those features feels like a big flaw. Hopefully, it's just me not knowing how to use the extension properly, but for now, I had to disable it.

At first, I thought the issue was related to my browser's cache or something similar, so I reset the browser, and that fixed it temporarily. However, once I reinstalled my extensions, the issue came back. After testing them one by one, I found out that the problem was caused by "Malwarebytes Browser Guard."

This wouldn't be such a big deal, but I use the aforementioned pages a lot and at least I think that many users also use Google Maps and from my experience, that's where the issue is the worst.