Connect to MariaDB in Host from Docker Container Application


I have been trying to have a docker application, mantisbt, to connect to a MariaDB that is running at the host of docker. But I cannot seem to get it to work. I keep getting an error of database has gone away.

I would really appreciate if anyone could help me with this.

Docker version: 20.10.3-1239
MantisBT Image: xlrl/mantisbt (tag: latest)
Host OS: Synology DSM 7.0.1


Good morning,
the IP-address to reach services on the Docker-host is (for Docker running on Linux) or host.docker.internal (for Docker running on Windows).