Hello Abigman,
thanks for reporting the problem.
First, can you make sure you the option "Settings > General > Show Avast tray icon" is checked.
Second, try to uncheck it, restart PC and check it again.
If nothing helps, please, upload log file "C:\ProgramData\AVAST Software\Avast\log\AvastUI.log" here in this thread and I will look into it.
Thanks
Manas from
Avast UI team