If this is about the MC form, I found that if I pasted my CC number (such as from a pass manager), it would bork unless:

- I entered the number

- Then moved to the front of the input field

- Deleted a char, and re-entered it, because

- an end-of-field char change removes the whole number

Wait a sec, even two seconds, and the number will auto-obscure.

Then it works.