With the new Teams only (Microsoft Teams Essentials (AAD Identity)) subscription you can add Teams functionality to users.
Included in this subscription is Exchange Online Kiosk which conflicts with existing Exchange Online Plan 1 and Plan 2 licenses.
Should you want to connect a Teams license to a user to whom an Exchange Online Plan 1 or Plan 2 license is assigned, please follow the steps mentioned below.
Sign into the Office 365 admin portal via https://portal.office.com
Click on the Admin icon and navigate to Users > Active users.
Select a user from the list of users who requires the Teams license
Switch to Licenses and Apps and assign the Teams license
Scroll down to the Apps section and uncheck the checkbox for (Exchange Online Kiosk) to disable it
Click on Save changes.