Unable to create background process from store process

I'm trying to background a process, and this is just an example code that triggers the behavior... I realize it isn't working code.

code:

case "$1" in
  "store")
    (
    while :
    do
      echo "sleeping..." > /dev/tty
      sleep 30
    done
    ) &
  exit 0
   ;;
esac
[...]

When I run the credential helper manually from the command line like this, it works and spits me back out to a command prompt:
echo '{ <JSON> }' | docker-credential-blah store

But when I use podman to log in:
podman login url.com

It asks for username and password (from the "get" process) but then just hangs once it gets to the "store" process.

I even tried moving the background code to a separate script and running that, but it still waits for that code to finish before continuing on. I think it must be waiting for all the child processes to complete.

Start by reproducing the hang with podman login url.com and the docker-credential-blah store example, then trace how the get and store processes are launched and waited on. Done means identifying why the background child keeps the store operation open and confirming the behavior is corrected without breaking the credential helper flow.