Hi!

In documentation:

Public dashboards are visible to all users.
Private dashboards are visible only to their owner. Private dashboards can be shared by the owner to other users and user groups.

https://www.zabbix.com/documentation/5.0/manual/web_interface/frontend_sections/monitoring/dashboard

But zabbix users are surprises to find later that Public mode actually enables READ access to all the users.
It's more expected to be like a global switch - is the dashboard is shared to below specified groups/users or absolutely Private one.

I'm personally agree with that expectation and I think that it may be confusing without reading documentation and remembering that specific behavior.

So, suggested to reconsider current behavior and make it more user friendly.