You might have entered a wrong value in username or address or any field you have to fill in a website in Chrome. And once filled and moved to next page, every time you go back to the same page it always suggests the wrong or previously filled value which you might not need now.
I encountered this issue where I was not knowing my AWS website login username, so I had tried many combinations and I used AWS website not so frequently and had many times tried using different usernames and all had been stored in history. So after few months if I come back to the website the suggested usernames were many, I again landed at square one where I had to again remember or search through emails to identify my correct username. Tried many ways to delete the auto fill suggestions, previously used usernames so that it does not show it again and should only show the one that is correct.
I got lot of suggestions to delete the Autofill form data from History, option shown below. However this would delete entire suggestions and I wanted only tweaks or remove only few of them. I had to remove address suggestions as well which I wrongly entered earlier and as the length was huge I was not be able to guess which one is correct from the suggestions as the wrong word was at the end and the suggestions showed up only few words at the starting and that was same for both the suggestions.
Somehow was lucky recently and found a solution for the same online. And found below steps easiest to follow and remember.
1. Open a web page in which a data field showing the problematic value appears.
2. Double-click (Select) the field to make it show its drop down (Auto Fill Suggestions).
3. Highlight the problematic value with your mouse or scroll up and down.
4. Once highlighted Press Shift+Delete
Now the deleted values will not appear as suggestions and AWS only showed me the correct username and was able to get rid of the hassle.
Let me know if this was able to resolve your issue or if you are looking for something else.