Question SFTP and chroot not working as expected

[IronDonDon]

I have rebuilt chroot template, which added '/usr/libexec/openssh/sftp-server' -> '/var/www/vhosts/chroot/usr/libexec/openssh/sftp-server' , but i still can't connect via SFTP.
FileZilla shows - FATAL ERROR: Received unexpected end-of-file from SFTP server
WinSCP - Cannot initialize SFTP protocol. Is the host running an SFTP server?

I am able to connect to the chrooted env. via ssh, with restrictions in place:
bash-4.2$ echo -n 'SFTP restrictions '; [[ -e /httpdocs ]] && echo 'active' || echo 'inactive'
SFTP restrictions active

sftp subsystem is set to:
Subsystem sftp /usr/libexec/openssh/sftp-server
if set to Subsystem sftp internal-sftp, then I am able to connect via SFTP, but users are able to leave their chroot env., which is not ok.

My server:
Centos 7.7.1908
Plesk Obsidian Version 18.0.26

Appreciate any help!
Thank you