I just launched a fresh Bitnami instance in AWS and could configure the cron jobs of the
bitnami@ip-172-31-20-195:~$ crontab -e
no crontab for bitnami - using an empty one
Select an editor. To change later, run 'select-editor'.
1. /bin/nano <---- easiest
Choose 1-3 :
As you can see, I had a crontab file for bitnami but it uses an empty one. Are you using a AWS Marketplace image or a community one? Can you share the AMI ID of that instance?