Trouble with Password Auto Fill on my iPhone

Trouble with Password Auto Fill on my iPhone 13 IOS 16.4.

When I go to particular websites (only a few particular websites) I’m unable to use the autofill username/password log in like I normally do. I recently noticed on these sites when the curser is in the username box the option below doesn’t say it’s normal message which is “Sign in with your saved password, (Username)” which is normally highlighted in blue, like a link. Instead on the websites that give me trouble it simply says “For this website use (Username)” not in blue but in regular lettering. However when I click on that it ends up autofilling it with my password and puts it into the username space. Then the curser jumps down to the password space with the same message and enters in the password again. AKA No Username plus I can never tell it’s even doing that since both are blocked out with *** or ••• (not showing me the letters). I almost lock myself out for incorrect credentials 3 times in a row.

In other words, there’s no way for me to autofill both my username and password in their correct spots to log me in like I’m able to do on almost every other site or app I have. 🤷🏻‍♂️

Is this an issue with my password auto fill or password keychain? Or is this because these particular websites have better security or something?

I should add that out of the few sites I have this issue on 2 are for my Pension and another is for my 401K.

If it’s a matter of those websites being more secure I kind of understand but at the same time why am I easily able to use the auto fill password to log into my IRS & DMV website accounts or the 4 different Bank apps and sites I have? It’s not the biggest deal in the world because I have my usernames for those sites saved in another folder on my phone. It’s just annoying since I never realize what’s going on since I can’t see the letters. I’d just like to know the reasoning behind this.

-Any explanation or thoughts on this are greatly appreciated. Thank you in advance, and sorry for writing so much trying to explain this issue.

[Re-Titled by Moderator]