Some websites have anti-autosave-password mechanisms that encode your password in Base64 when you click login, so the auto-saved password becomes a Base64 string that cannot be entered directly.
When I set the password correctly, each time I log in, it prompts me to update the password.
When I save it for the first time, I get an option to disable auto-save on this website. However, the password update pop-up only offers "Yes", "No", and "Delete Password".
By the way, I’m not fluent in English(I used AI to make this sentence better), and my Firefox is not in English, so the option names might be inaccurate.=(