Yesterday, while out flying, I tried to go to tripod mode and after clicking on the control icon of the main screen, it opened the flight modes just fine. But when I touched the screen to slide it over to where the tripod mode was, it wouldn't slide. Never had this happen before. Any ideas for me to try? I am using a new iPhone 11(which just doesn't fit the controller very well). My iphone 6 worked just fine. All other functions worked great. Precision landing was outstanding as always.
One other question, does the controller have to be in the "T" position as well as the one on the screen? Tripod mode does not work with just the controller in "T" position.

If your talking on the Mavic 2 then yes the controller needs to be in the T position.
On the original MP make sure the controller ins in the P mode.

Thank you, apparently, I don't have to use the screen icon, just toggle the mode button.