Hi Lindsey,
I just had that happen too. I had a pop-up on my phone ask that I verify my identity by entering my Apple ID Password. Tried 3 times without success. I double checked by logging on to icloud on my laptop. no problem. Again tried to enter my Apple password in the pop-up request. no luck. went around the pop-up by going thru SETTINGS, clicking on iCloud. The iCloud login screen appeared. Entered my user ID which is also my (maybe everybody's) Apple user ID, and my password associated with my Apple ID. It worked. I'm in the app so all is good for the moment. I'd like the pop-up to come up again just to try to see if my successful login has corrected the password glitch in the pop-up. Let me know if this works for you.
ELB3