Contributors not showing in the Author box on 5.9

I have updated my multi-author website twice on 5.9 from 5.8

On the first attempt, I was running php 7.3, upgraded to wp 5.9
On the second attempts after a month, I switched to php 7.4, upgraded to wp 5.9.1

In both attempts, in the author list (author box) of new post, I can see only those users who have publishing right. Contributors are missing from the list.
On the users tab of the dashboard, I can see all users.

I have cleared the cache, and rebooted the machine.
What steps should I take to resolve this issue? Being stuck to 5.8 is not good.