BuddyPress.org

Found a temp way to change the Avatar problem, I use FTP and find the folder ID in group-avatars folder for the Group and found all those images that I tried to uploaded in Group Admin to replace the Group Avatar and pick one and add “-bpfull” to the file name. e.g. filename-bpfull.png and it worked at least for the testing! But hope there is a better way to do it from the Front End.