I had heard that the recent update causing conflict between update and anti-virus. https://www.bleepingcomputer.com/news/microsoft/windows-is-slower-after-april-2019-updates-according-to-users/
Today, my PC just froze while gaming. It wasn't BSOD this time. Reseted and all of sudden my pc ran extremely slow. explorer.exe, chrome, cmd... takes long long time to open and respond, Chrome ramdonly froze and won't load the page...
I'm using Windows 10 1809 with update KB4493509 installed few weeks ago.
I checked the eventlog I saw malwarebytes service stopped working many times