I am seeing this condition as well. But here's the sidelight.
The Avast icon shows "system is secured" as long as Automatic Updates are enabled. If I try using "Ask" or "Manual", it shifts to "system is not fully protected" as soon as I click OK to set the new condition for updating. If I go back to "Automatic", system is once again secure.
I would rather see this warning if there is actually a new update available.