configuration – MariaDB doesn’t read all options from /etc/mysql/conf.d/ after upgrade

I am using Ubuntu 20.04LTS. I upgraded Mariadb 10.5.5 to 10.5.8 using mariadb’s own repositories. After upgrade I noticed API server was unable to connect to DB server through private network. After some tinkering, I realized mariadb is no longer reading bind-address from /etc/mysql/conf.d/customizations.cnf and was listening to 127.0.0.1 instead of 0.0.0.0. Then I proceeded to adding bind-address to /etc/mysql/my.cnf and then it worked again.

/etc/mysql/mariadb.cnf is the config used. It is symlinked to /etc/mysql/my.cnf. Which contains line !includedir /etc/mysql/conf.d/
All the other configurations such as innodb_buffer_pool_size are still read from file: /etc/mysql/conf.d/customizations.cnf, but bind-address is not. Why is that? And yes its under [mysqld].

My /etc/mysql/conf.d/customizations.cnf:

[mysqld]
bind-address = 0.0.0.0
skip_name_resolve=1
innodb_buffer_pool_size=20G
max_connections=550

[mariadb]
log_error=/var/log/mysql/mariadb-errors.log