In the Safari browser you have to make settings change to enable the tablet-friendly version of Stock Rover.
The setting change can be done in the browser by clicking on the AA in the URL of the browser and then select Website Settings, as seen in the screenshot below.
In the Settings window, confirm the Request Desktop Website is turned off, as seen in the screenshot below.
After making the change, log out and log back into Stock Rover and you should now see the downward triangles to access the right-click menus.
