TimeZone Setting On PostgreSQL Databases

I have a **Patroni cluster** with two **Ubuntu 22 db server**. The timezone of my instances was set to **UTC**. I have needed to edit them to set the local timezone to **Europe/Istanbul**. I have made the timezone change on OS-level. When i checked the timezone setting with timedatectl command, i saw local time was correct. And, I applied the setting one by one to all my databases on my server:

DATABASE "db_name" SET TIMEZONE TO "Europe/Istanbul";

Also applied the setting:

ALTER SYSTEM SET TimeZone TO 'Europe/Istanbul';

And i edited my patroni config file and entered timezone setting like:

: Europe/Istanbul

After that, i restarted my patroni cluster. After restarting my cluster, i saw that some of databases had applied the changes but other ones had not. I checked those databases configuration. The configuration was same with the applied ones. I still see old timezone setting which was ETC/UTC when I execute sql command below:

timezone

I am a little bit confused about it. Strange situation. What might cause the situation? Do i miss something?