I have 2 identical PC’s running AV Free. I uninstalled V21.7 (old logo) and installed V21.8 (new logo) however one PC has a slightly different UI to the other (see attached pic).
Hi,
This is expected behaviour. We are currently testing some changes in the user interface, and some Avast installations use this new UI already. This is normal, and there’s nothing to be concerned about.
Thank you for your reply. My OCD can now calm down! 
You are welcome.