I am having no trouble changing and saving profile data. What IS missing seems to be the notification success message that usually pops up and then fades away.
I am also seeing some off behaviour on forum popups. If you click on the new posts popup – or the about SP popup, then you will notice that they first open up in the top left hand corner and then suddenly move to the middle of the display. When you close them they jump back to the corner before disappearing,
My hunch is – and at the moment it is just a hunch – is that the profile success message IS being shown but is being positioned off-screen so you never see it. I don’t see any noticeable evidence that it is just styled to not show up although that could be considered.
There us a vast amount of javascript being loaded – 90 separate S files as it happens – many of which appear to be display items. If you have started to use some new plugins in recent times it might be worth deactivating them briefly just to test and see if they are the cause. knowing the root of the problem is half way to solving it!