Unable to Reset Root Password in Ubuntu 18.04 LTS

I followed the tutorial for resetting root password and was emailed a temporary password. I launch recovery console for the droplet (since it didn’t have direct console access yet) and enter the user as “root” and enter the temporary password. It then asks me to create a new password. I do this and then the screen goes blank and asks for me to log in again. But only the temporary password emailed to me works, and it never saves the newly created password no matter how many times I try this. This is a repeating loop and I can never actually log into my console. I think this is due to no available disc space. Should I simply upgrade the Droplet plan to higher storage and then re-attempt to update the password? Please help! I am a beginner by the way, so I am new to servers. Thank you.