I am in Florida and have found that I have to fly either early evenings or early mornings before the sun gets bright. Also heavily overcast days are also good. The sun is just too bright. Does not matter which drone/controller I use I can not see anything on my phone or the controller.
I found out about HugeRock and their X7 tablet on youtube. Now it is rather expensive at $500 but, it can be adjusted up to 2600 nits! You can get it on Amazon along with a variety of mounts for different controllers.
A total game changer! I can fly at any time regardless of how bright the sun is. Super clear, bright view.
I know it is not cheap, and I am not a rich man, but I have 3 different drones, batteries, etc and to use them only when the sun is not bright just seemed to be a waste.
Well worth the money in my opinion.