Whilst this may seem strange to ask - what avast version do you have (free, pro, AIS, premier) ?
If it is one of the paid versions also, then you should be able to switch off ads - avastUI > Settings > General > Popups disable the ‘Show popup offers for other avast products.’
I think that is the problem, you are effectively getting ads from the avast free program - which is dumb - as it isn’t smart enough to recognise your license for the VPN and Cleanup.
I don’t know if there is a way to get round this or not.
If you log on to your my.avast.com account and check the License section of that, does it show the licenses there ?
Anyone considering contacting Avast by email, don’t waste your time, I have been trying for more than a week now with no reply, and did it through ‘Contact Us’ on avast.com.