Failing to connect applications via MaxScale - mariadb

Question

I have 3 node Galera Cluseter and a node for maxscale. the problem is only maxscale user i have defined in maxscale.cnf can connect to cluster via listener service. all nodes are in local network and can see each other.
maxscale.cnf
[maxscale]
threads=1
[Galera-Monitor]
type=monitor
module=galeramon
servers=server1,server2,server3
user=maxscale
password=qwe123
monitor_interval=1000
[Read-Write-Service]
type=service
router=readwritesplit
servers=server1, server2, server3
user=maxscale
password=qwe123
[Read-Only-Service]
type=service
router=readconnroute
servers=server1, server2, server3
user=maxscale
password=qwe123
router_options=slave
[Read-Write-Listener]
type=listener
service=Read-Write-Service
protocol=MariaDBClient
port=4006
[Read-Only-Listener]
type=listener
service=Read-Only-Service
protocol=MariaDBClient
port=4008
[server1]
type=server
address=192.168.122.93
port=3306
protocol=MariaDBBackend
[server2]
type=server
address=192.168.122.17
port=3306
protocol=MariaDBBackend
[server3]
type=server
address=192.168.122.13
port=3306
protocol=MariaDBBackend
root#maxscale:~# mysql -umaxscale -pqwe123 -h192.168.122.222 -P4006
Welcome to the MariaDB monitor. Commands end with ; or \g.
root#maxscale:~# mysql -umyuser -pmyuser -h192.168.122.222 -P4006
ERROR 1045 (28000): Access denied for user 'myuser'#'::ffff:192.168.122.222' (using password: YES)
root#sky:~# mysql -umyuser -pmyuser -h192.168.122.17
Welcome to the MariaDB monitor. Commands end with ; or \g.
MariaDB [(none)]> show grants for myuser;
+-------------------------------------------------------------------------------------------------------+
| Grants for myuser#% |
+-------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'myuser'#'%' IDENTIFIED BY PASSWORD '*CBA73BBE5D9AF59311C3F4D7E8C20AA847F7B188' |
| GRANT ALL PRIVILEGES ON `mydatabase`.`pet` TO 'myuser'#'%' |
+-------------------------------------------------------------------------------------------------------+
As you can see myuser have problem in connecting via maxscale node. How I can solve this problem and make so any application connect to maxscale with their own user.
edit:
This is my maxscale user permissions:
MariaDB [(none)]> show grants;
+--------------------------------------------------------------------------------------------------------------------------------+
| Grants for maxscale#192.168.122.222 |
+--------------------------------------------------------------------------------------------------------------------------------+
| GRANT SHOW DATABASES ON *.* TO 'maxscale'#'192.168.122.222' IDENTIFIED BY PASSWORD '*8DCDD69CE7D121DE8013062AEAEB2A148910D50E' |
| GRANT SELECT ON `mysql`.`db` TO 'maxscale'#'192.168.122.222' |
| GRANT SELECT ON `mysql`.`user` TO 'maxscale'#'192.168.122.222' |
+--------------------------------------------------------------------------------------------------------------------------------+

Answer 1

Base on this useful link: https://mariadb.com/kb/en/maxscale-troubleshooting/
Check the below privileges on your nodes configurations:
GRANT SELECT ON mysql.user TO 'maxscale'#'maxscalehost';
GRANT SELECT ON mysql.db TO 'maxscale'#'maxscalehost';
GRANT SELECT ON mysql.tables_priv TO 'maxscale'#'maxscalehost';
GRANT SELECT ON mysql.roles_mapping TO 'maxscale'#'maxscalehost';
GRANT SHOW DATABASES ON *.* TO 'maxscale'#'maxscalehost';