I was on 1.7.50 and updated to 1.7.58, after which the new autologon to webmail option is not working and roundcube shows 403 error.
workaround:
cd /usr/local/mail/openmail
docker --context default compose down roundcube
rm -rf /usr/local/mail/openmail/roundcube-plugins/autologin.php
wget -O "/usr/local/mail/openmail/roundcube-plugins/autologin.php" https://raw.githubusercontent.com/stefanpejcic/OpenMail/refs/heads/main/roundcube-plugins/autologin.php
wget -O "/usr/local/mail/openmail/roundcube-plugins/dovecot_impersonate/dovecot_impersonate.php" https://raw.githubusercontent.com/stefanpejcic/OpenMail/refs/heads/main/roundcube-plugins/dovecot_impersonate/dovecot_impersonate.php
docker --context default compose up -d roundcube