Not allowed to connect to Mysql error in docker

From time to time i receive this error while running the official mysql image in docker:

An exception occured in driver: SQLSTATE[HY000] [1130] Host ‘172.17.0.5’ is
not allowed to connect to this MySQL server

The reason for this is not quite clear yet but i usually resolve it like described here.
Note that all data stored in the project will be lost!
So this error is quite annyoing but luckily i work on fixtures so i can restore data easily.
These steps let me connect to the mysql container again, at least.

1. Run an inspection on the mysql container:

docker inspect my-project-with-mysql

And search for the data mounts of the mysql container to know where the data is stored on my machine because i need to delete them, aargh:

{
   "Mounts":[
      {
         "Type":"volume",
         "Name":"db9aa2f8a43c08",
         "Source":"/var/lib/docker/volumes/db9aa2f8a43c08/_data",
         "Destination":"/var/lib/mysql",
         "Driver":"local",
         "Mode":"",
         "RW":true,
         "Propagation":""
      }
   ]
}

The path can be found in the “Source” property.

2. Now i remove all containers to start anew:

docker-compose rm my-project-with-mysql

3. Then i remove all data in the mysql container. My assumption is that somehow the data in the system tables got corrupted.
So delete all contents and restore the directory:

sudo rm -rf /var/lib/docker/volumes/db9aa2f8a43c08/_data
sudo mkdir /var/lib/docker/volumes/db9aa2f8a43c08/_data

4. Finally rebuild the containers

docker-compose build
docker-compose up

5. Now i run the scripts that will populate the database from the fixtures again and the problem is fixed.

If you know the reason for this error please let me know.