Add-On container doesn't want to start OCI shim

I get the below error when I want to start my add-on. I am using an alpine image, just not the HA one. How can I resolve this issue?

400 Client Error for http+docker://localhost/v1.41/containers/48e25bb0c8378f8e7217493166b181f0f95cf5e764d0baf56884f625978684db/start: Bad Request (“failed to create shim: OCI runtime create failed: runc create failed: unable to start container process: exec: “/entrypoint.sh”: permission denied: unknown”)

It starts and runs without issues on docker desktop.

Anybody any idea in which direction I need to start looking?