I don't think I have ever had 1Password get entries wrong. Some sites seem to do something to block it, and every now and then 1Password doesn't enter the state for addresses (given the variety of user experiences for that, it's not surprising).
Don't blame CapitalOne, it is 1P's fault for offering a broken feature: if you can't properly update an "update password" form, don't offer to do so. Like tesla and its bogus FSD.
I've been changing some passwords and 1P constantly overwrites the password it just generated or when I click on a password to change it overzealously copies it which means i repeatedly have to go back to the generated password vault look at the history and copy it into the password entry. LastPass was a bit less trigger happy with the click-and-copy and smarter in detecting when a password changed. Like I said, both have bad UI, 1P is just a little worse than LP.
In my experience, this is often not a matter of "doing something", but rather a matter of "not doing something [correctly]". If a site does not properly tag an input field, then password managers (and other applications) will have trouble finding it.