Hi!
so, this problem happens when u try to change azure ad b2c policies. I guess u can fix it by editing JavaScript and HTML in your custom policy. actually 'verify' button and progress bar work based on the page layout and JavaScript in your policy. and by default, azure ad b2c doesn't turn off the 'verify' button or keep the progress bar showing after clicking.
If this was helpful, please accept the answer.
rgds,
alex