Firefox stalls displaying pages with code in Stackoverflow or github, while chromium doesn't

Question

I'm running Ubuntu-16.04.6 LTS on NVIDIA TX2 (L4T R28.2.0). When using firefox(66.0.2), I'm experiencing long stalls (sometimes Ubuntu gets dark) when browsing pages with code in stackoverflow or github.

With firefox when it lags I can see a CPU at 100% with htop. It doesn't happen with chromium (73.0.3683.86).

Does anyone know this issue, and further a fix or workaround ?

Answer 1

Seems it is a known bug... Why do fixed elements slow down scrolling in Firefox?

The workaround is to disable smooth scrolling in firefox preferences.