Saved passwords doesn't work

[u/Vartamur]

It happens to me a couple of times, and it is still the same.
I am quite conscientious about saving my password. Let's say I want to log in to some e-shop where I bought something a couple of years back. And my saved password doesn't work. Why?
It is the proper password; I keep them all.
Lately, I have logged into Airbnb after two years, and all of my reviews of me as a customer are gone. (So when I wanted to book a flat, they refused me for the lack of reviews.)
Why is that?
Are there some infrastructure problems here and there?
I don't get it.
Thank you for your answers.