"An Unknown Error Has Occurred"

For reasons beyond me, I cannot change my iCloud password. I did not forget the current one, but as I start typing a new one, it says "too weak," and once I meet all of the requirements, it says that "an unknown error has occurred." Please see the screenshot attached for more info. Also note that I do have 2-factor authentication enabled.

Thanks to anyone who may be able to help on this one!

–diodes123