Several times a day when I see I have an email the yahoo mail app goes black, or sometimes white, and just hangs. Rebooting seems the only solution, but of course it shouldn’tbe happening in the firdt place.
Have you tried clearing the Yahoo mail apps’ cache?. (I use yahoo mail but not the app, I go through the Chrome browser).
Just a thought.
I have tried your suggestion. Time will tell whether it works. Thank you.