I use for testing in the virtual machine (Ubuntu 16.04), for me, I fixed the error changing the file 50-server.cnf
.
My server is Ubuntu, so changing the file below:
50-server.cnf
The path of this file:
/etc/mysql/mariadb.conf.d
PS: Create a backup of the file before the change.
Only change in file the bind-address 127.0.0.0
to bind-address 0.0.0.0
After this restart service and try again.
Regarding that user, need to allow for external connections.
I hope that this info helps you.