Under Tickets, the button Follow-Up is not showing in Tablet UI, only in HTML5.
The button is in a different place in this UI
In Tablet UI, the follow up buttons are available in the Facet Related Items and within that there is a table showing all Follow items.
The menu on that table contains those actions.
Please enable the Related Items facet via adaptation for RUI Ticket UI.
KBA , LOD-CRM-SRP , Service Request Processing , How To