I've been having big problems with my Malwarebytes Premium and Windows 10 2004. Chalk me up with the others that have been reporting this problem.
Computer runs fine for a while, then network connectivity drops out in web browsers (Firefox and Chrome), the browsers lock up, and various Windows components and other applications stop responding as well. I've been dealing with this for a while on my desktop system, which is a custom build. In desperation, I wiped my whole system and reinstalled Windows 10 2004 fresh last night and reinstalled all my applications, including the latest (non-beta) MWB Premium. Within hours, the problem returned.
It's a custom gaming rig that I have overclocked, and before wiping Windows last night and reinstalling, I've been tweaking my system BIOS settings and clocks thinking it had to do with overclocking instability, but I was running stock clocks last night when the problem returned immediately after clean reinstallation.
I was ready to chalk it up to a problem with Windows and my custom build, until my laptop did the SAME EXACT THING today, a day after updating it to Win 10 2004. Browsers lock up, network connectivity slows to a crawl, apps become unresponsive, and restarting Windows (without hard power cycle) takes 5-10 minutes!
My desktop is a Skylake i7-6700k in an Asus Maximus VIII Hero, using both Intel's iGPU and an Nvidia 2080T1.
My laptop is a Lenovo T470s.
Both systems are current on drivers and Windows updates.
Really hope there's a solution for this soon!