Mouse scrolling stops functioning while scrolling on Facebook.
The only way i am able to suggest reproducing it was to use Facebook and see what happens.
I will add I am using the Facebook Purity extension with my brave browser.
The actual result is basically the scrolling using the mouse wheel stops responding to input. I can click the up and down arrows on the browser and drag the little block up and down.
This happens not super often, but its at least once each time I use the browser. a refresh of the page usually makes it work again but sometimes it comes back right away.
Brave Version - Version 0.62.51 Chromium: 73.0.3683.103 (Official Build) (64-bit)
Windows Version - Win 10 Pro, 64bit, Version 1803, build 17134.706