Failed to load Pure cloudops configuration

We often get error “failed to load Pure cloudops configuration: failed to get Pure secret px-pure-secret: Failed to get secret [px-pure-secret]. Err: Unauthorized” on kubernetes cluster nodes that have been rebooted. Whilst this error is present, portworx PVCs cannot be used on that node.
Restarting the portworx.service fixes the problem.
Has anyone else encountered this problem, and found a fix for it?
This is an on-prem kubernetes cluster, with on-prem flashblade.