DocFraggle I suggest you edit your data/Dockerfiles/unbound/healthcheck.sh script and add some debug log output starting at line 53
For example, output the details of the dig command in $dig_output and maybe even the return code. The script just checks if rc=0, but maybe it’s not 0, dig can return multiple return codes apart from 1
The script may still run things differently from you running commands inside the container
Which brings me back to my suggestion from above… why don’t you have a deeper look and log the details from the healthcheck script?