The problem with ftp (jail)

I uploaded a backup created on Hestia Control Panel v1.8.12 (ubuntu)
to a new server running Hestia Control Panel v1.9.4. (debian)

After restoring the backup, I got an issue with the FTP user admin.
I can’t transfer files normally — the FTP client freezes, some files upload and some don’t, there are lags, and overall it’s impossible to upload or edit files via the admin FTP user.

I have only one user — admin, and all 80 websites are under this user.

As I understand, the new version of Hestia adds new vsftpd config variables:

local_root=/srv/jail/%u
user_sub_token=%u

Apparently something related to jail.

What should I do and which commands should I run to make the FTP user admin work normally again on port 21?