Go to Menu Items

Select the app you want, in our case CRM

Then in “Action” select : ir.actions.act_window

And chose the menu you want, in our case “Teams”

Don’t forget to refresh the page after the change in order to update the modification

Now when you click on CRM, the default “landing” page is Teams

Be aware that this change might not stay if you upgrade. You’ll just need to redo the process