Flatsome Theme: Save button not working anymore?

Hey, I am using Flatsome Theme 2.7.5 and suddenly when I go to Appearance-Theme Options and make any changes, if I click the blue Save all Changes button nothing happens anymore.
This is very annoying because I have to update several things.
Anyone knows the reason?
Thank you

Could be anything but you should contact the theme author for support

well, not sure if has anything to do with the theme at all. Just mentioning the theme here. But it worked without any problem, suddenly it stopped, and I did not update the theme or something. So it is more than likely that there is some other reason