chsh: /etc/passwd.20598: Permission denied

Question

I've given an Ubuntu 18.04 box with user account which have root permission but not use /bin/bash as default shell. Hence, when I ssh to it, when I hit left, right, up, down ←↑→ keys, it will produces ^[[D ^[[A ^[[C

I want to change the user to default use /bin/bash shell with

sudo chsh -s /bin/bash {MY_USERNAME} 

but the terminal says:

chsh: /etc/passwd.20598: Permission denied 
chsh: cannot lock /etc/passwd; try again later

How could I fix it?