Members could not save their edited profile

HI,

I have allowed my members to edit their profiles by checking the ”
Can edit their profile?” at the general permissions of their role setting.

Then, my members are able to see their profile and able to edit, upload profile picture, or fill in their information at their profile page, BUT they couldn’t save it. There is a save button but the button seems like couldn’t work.
Once they refresh the page or go to other page, the info they edited / pic uploaded will be gone.
(I am using the default ultimate member profile form)

Anyone can help with this problem ?