The Awazon login places a couple of fake input fields next to the real one, and their names rotate on every page load. This is a honeypot. Automated fillers put credentials into the wrong field, the trap trips, and the script never reaches the real login.
For you, the rule is simple: type into the visible real field only. If a password manager is filling a hidden decoy field instead of the one you can see, fill the visible field by hand. The rotating names are why a cached script cannot log in, and why occasionally a manager needs a manual nudge.
The captcha is six characters and case sensitive, so match the case exactly.