Hello,
I created a "Manager" user and gave him permissions to access the K2 administrative interface, but not to K2 users management and options. In the backend (from the left menu) this user can access articles, categories, tags, comments and media manager, while he has no access to usersmanagement and K2 parameters. However from the main joomla menu (Components -> K2) the same user has access to all K2 submenus, and even if Joomla shows the "no auth" notification, in fact the resources are displayed anyway (It seems like a bug, see screenshot below).
How can this situation be corrected?

imgur.com/a/LUS3e

Hello and thank you for your feedback,

These links are menu item links. I will need to investigate this.

Thank you for your wonderful work!

Is there a simple way to avoid showing submenus in menu "Components -> K2" leaving only K2 visible and working?

The best approach would be to use a custom Admin Menu to show only the menu items you want.