Roundcube: "Unable to connect to the database!"

ok, I installed it again. I hope the former trouble will not occurs again.

[root@ns ~]# rpm -qa | grep roundcube
nethserver-roundcubemail-next-1.5.3-1.ns7.noarch
[root@ns ~]#
[root@ns ~]# systemctl status rh-mariadb105-mariadb@roundcubemail.service
● rh-mariadb105-mariadb@roundcubemail.service - MariaDB 10.5 database server
   Loaded: loaded (/etc/systemd/system/rh-mariadb105-mariadb@.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/rh-mariadb105-mariadb@roundcubemail.service.d
           └─nethserver.conf
   Active: active (running) since Mon 2022-03-28 16:00:17 CEST; 1min 32s ago
     Docs: man:mysqld(8)
           https://mariadb.com/kb/en/library/systemd/
 Main PID: 19330 (mysqld)
   Status: "Taking your SQL requests now..."
   CGroup: /system.slice/system-rh\x2dmariadb105\x2dmariadb.slice/rh-mariadb105-mariadb@roundcubemail.service
           └─19330 /opt/rh/rh-mariadb105/root/usr/libexec/mysqld --defaults-group-suffix=.roundcubemail --basedir=/op...

Mar 28 16:00:17 ns.myserver.de systemd[1]: Starting MariaDB 10.5 database server...
Mar 28 16:00:17 ns.myserver.de scl[19285]: Database MariaDB is probably initialized in /var/opt/rh/...one.
Mar 28 16:00:17 ns.myserver.de scl[19285]: If this is not the case, make sure the /var/opt/rh/rh-ma...dir.
Mar 28 16:00:17 ns.myserver.de mysqld-scl-helper[19330]: 2022-03-28 16:00:17 0 [Note] /opt/rh/rh-mari.....
Mar 28 16:00:17 ns.myserver.de mysqld-scl-helper[19330]: 2022-03-28 16:00:17 0 [Warning] Could not in...4)
Mar 28 16:00:17 ns.myserver.de mysqld-scl-helper[19330]: 2022-03-28 16:00:17 0 [Warning] Changed limi...0)
Mar 28 16:00:17 ns.myserver.de systemd[1]: Started MariaDB 10.5 database server.
Hint: Some lines were ellipsized, use -l to show in full.
[root@ns ~]#