Until we have a fix - here is exactly what you can do.
- Close Brave
- Go to your profile folder. This should be like
%LOCALAPPDATA%\BraveSoftware\Brave-Browser\User Data\
- Open the
Local State
file in the editor of your choice - Search to find
avatar_icon
- change the value to
chrome://theme/IDR_PROFILE_AVATAR_26
- Save the file
- Relaunch Brave