docker compose down results in "Error response from daemon: cannot stop container: permission denied"

hello community,

i have setup a docker compose stack with an web service and a mariadb container. (iam using `image: mariadb:10.3` to replicate a old server setup..)

for a long time in developing and testing this setup it all worked.. for some short time now i get a permission denied when i try to *down* the compose setup:

docker-compose-myapp (main *)$ docker compose down    
[+] Running 1/1  
 ✘ Container myapp-db  Error while Stopping                                                                                                                                                                                                                                                                   14.1s   
Error response from daemon: cannot stop container: ef6xxxx8c: permission denied  

it seems the container has a client connection open that never closes - i have no idea from what that comes - all other services are already stopped...

so i hope anybody can give me some hints on how to debug this!!

:-) iam open for every tips and hints!

sunny greetings stefan