Shared board visible but content not loading for other users

I’m experiencing an issue with the Whiteboard plugin in Nextcloud when sharing boards internally with other users.

Setup:

Nextcloud instance (self-hosted) V Nextcloud Hub 10 (31.0.9)
Whiteboard plugin installed and working for the creator V 1.5.7
No Live Server / WebSocket server configured

Problem:
When I create a whiteboard and share it with a colleague:

The colleague can see the whiteboard in their Nextcloud interface
They can open the whiteboard
However, the board appears completely empty (no content is visible)

The original creator can see all content without any issues.

Expected behavior:
The shared user should see the same whiteboard content as the creator.

Question:
Is a Live Server (WebSocket backend) required for proper synchronization and rendering of whiteboard content between users?

Or should basic viewing of existing content work without it?

Additional notes:

Permissions seem to be set correctly
The issue is reproducible with multiple users
No obvious errors in the UI

Any guidance on required configuration or missing components would be appreciated.

Reproduce the issue by sharing an existing board with another internal user on Nextcloud Hub 10 with Whiteboard 1.5.7 and no Live Server/WebSocket backend. Start by checking whether the recipient can load persisted content without that component; done means identifying the required configuration or confirming a reproducible loading defect. No files or tests are named.