Bug description
After successful upgrade from 2.17 to 2.18 I was asked to enter a new password. Now I'm facing a fresh installation without any config.

Expected behavior
All configuration is kept during upgrade progress.

Steps to reproduce the issue:
What I did:

1. everything works well.
2. updating all nodes:

docker service update --image portainer/portainer-ce:latest --force portainer_portainer
docker service update --image portainer/agent:latest --force portainer_agent 

3. refresh login page
4. enter username and new password
5. all config was gone.

Technical details:

• Portainer version: 2.18.2
• Docker version (managed by Portainer): 23.0.5
• Platform (windows/linux): debian
• Command used to start Portainer (docker run -p 9443:9443 portainer/portainer): is up and running in swarm mode since months.
• Browser: Chrome
• Have you reviewed our technical documentation and knowledge base? Yes

Additional context
Do you have ideas of a possible reason and how to restore the existing coniguration?