Since this is still at the initial test/deployment stage I think the easiest solution is to delete your deployment helm delete ..., ensure your PVC is deleted (if it’s not then delete it manually kubectl delete ...), and deploy again from scratch. If it works then you’ll have a known good baseline that you can start modifying.
The alternative is to obtain a shell inside the hub pod and examine the permissions and ownership of the volume, and then fix them if necessary by running a separate root pod. The first option is definitely easier 