if 1P7 autofills password website doesn't recognize it. Whenmanually enter password it is accepted.

Some sites have a limit on the length of a password but don't tell you what it is. They may appear to accept the password you registered but silently record a shortened version, omitting the last few characters.

You get the effect you have found when this situation occurs. You could try and find out what the site accepts, or just keep modifying your password, deleting one character at a time, until autofill works.