Typed word and autocomplete still suggests word i already finished typing
Even after I finish typing my word, it still suggests the word I just typed so if I hit enter to make a new line, it replaces the word with the exact same word, making me type slower. How do I turn this off without having to disable autocomplete?

I came to report the same issue. This just seems like a slight design oversight.
However I'd like to add one more point: if the typed word matches exactly one of the suggestions and one of the confirming keys (tab or enter) is pressed, the typed key should always go to the document and not act as a suggestion confirmation.
In other words, even if there are other potential matches, typing the full word of a suggestion should act as its own confirmation and not just select a longer completion. That is, I would recommend continuing to show "False" as the selected suggestion in the above example even if it is fully typed out, but to not absorb an enter or tab that immediately follows it.
This way if you have two suggestions, say "Foo" and "FooException", that typing "Foo" and hitting enter would not complete it to "FooException" unless you were to type say "FooE".