Received beta update to v.21.1.2449 
This could be the old chestnut of Avast not changing the version number of the last beta/pre-release number when it goes live.
Something which has confused from its introduction some time ago.
I think you need to do a restart and check the version and build number to see if that has actually changed.
Note my signature "avast! free 21.1.
2449 (build 21.1.5968.561) UI-1.0.597/" has a different build number from that in the first post "(build 21.1.5957)"
You may need to try a manual program update.
