Issue FTP Accounts automatically logged-Out (same with SSH access-/bin/false)

[hasaanch]

Hi there,
I am having problems with FTP and SSH access. After creating a new user from the FTP access section when I try to access the FTP it first opens the connection and immediately after that the connection is dropped. The same thing happens with SSH access. The connection is opened and immediately closed afterward.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Sun May 2 16:23:31 2021 from 103.150.206.26
Connection to tukarpani.com closed.

I got to fix the issue by editing the /etc/passwd file and changing the ':/bin/false' after the user to ':/bin/sh'

It fixes both the FTP and SSH access. But I have to do it with every account and I assume that's not the correct way to do it. Can you please tell me what might be the problem is?