Hi @teeboy4real
The buddypress core function “bp_get_user_has_avatar” is the function you are looking for. If this function returns false and you have Leira Letter Avatar plugin active them it means user is using a letter avatar.
This method is used by BuddyPress Profile Completion core functionality and i added support for it in release 1.2.1.
In the other hand, I was checking everything during the weekend to determine what could be happening with your site. What i think is happening is as follows: Buddypress Profile Completion saves a metatag once a user profile is complete, at the moment you installed Leira Letter Avatar, there was no compatibility between both plugins, so Profile Completion was taking the letter avatar as a user uploaded avatar, therefore, user metatag was set as well. A solution it could work is basically delete manually this metatag for all users, running a simple SQL script (dont worry Profile Completion will re add this metatag automatically) and the other option is to create a simple function to bypass this metatag to tell Profile completion if user really have or not uploaded an avatar, i could help you with it.
I hope it helps, let me know if you have any updates.