Well, I leave it, it's just a trifle and maybe only with me?
But...OK last try, I changed the file dimensions a bit to two versions: even and odd px and .png and .jpg and moved the crop window.
This time tested in Chrome.
On your demo site:
Suzan K. uploaded from the backend
User Demo uploaded from front end.
Same result: Already when approving the images you could see that there was / will be a difference.
And one more strange thing I just notice: Suzan (from backend) has info on stream that she changed Avatar a few minutes ago.
Demo User (uploaded from frontend) - although I changed the avatar several times after Suzan - still has info that the profile was updated an hour ago???