@nirmalts said in pfSense becomes sluggish at times:
for a window of 2-3 hrs everyday.
Your check list is quiet complete.
Even the most smallest pfSense capable devices like these can crank out several tens of megabits per second, nearly always limited by what happens upstream.
The solution is easy : don't use VPN suppliers during that observed windows.
Remember : they all work with the "best effort" methods. And it seems that legal video streaming services ran out of 'not seen' content so the less legal providers are even more used. Which explains the massive "VPN" usage and it's consequences.