I'm facing this issue as well on a Mac with Version 90.0.818.62 (Official build) (64-bit). I played around with https://www.w3schools.com/howto/tryit.asp?filename=tryhow_html_autocomplete_off and I guess I found a workaround.
With the default I get the auto suggest even at the first input field, see
screenshot.
While playing around with it I found out when I add another input field just behind for whatever weired reason the autocomplete doesn't appear for the input field where it was turned off, see screenshot. It can even be hidden. Form looks like this:
<form action="/action_page.php">
First name: <input type="text" name="fname" autocomplete="off"><input type="text" name="dummy" style="display:none"><br>
Last name: <input type="text" name="lname" autocomplete="on"><br>
<input type="submit">
</form>
Also the auto suggest for the second fields looks a little different, see screenshot. Maybe it's a different mode in Edge?!