Apple Mail app, yahoo inbox is suddenly empty

On both my iPhone 6s and my iPad running IOS 9.2, using the Mail app, my Yahoo inbox says it has no messages. The IOS was updated to 9.2 on both devices when it came out. Both devices have been running fine for weeks. This problem occurred today simultaneously on both devices. All the other folders have their messages, but the inbox is empty and will not update or refresh. The Google mail is unaffected. I'm running one Yahoo and one Gmail account on my Mail app. Out an abundance of caution, I went to Yahoo Mail on safari and moved all of my inbox items to a new folder to prevent loss. I have also turned off my Yahoo email on the Mail app. I've done a soft reset on my iPhone. I've tried logging the Yahoo Mail back on, but there is nothing in the inbox. I ran across some folks with Gmail problems with 9.2, but I haven't seen anything like my problem being discussed. I've left my Gmail running on Mail as I'm less concerned if things go missing.

Anyone else having a problem running their Yahoo mail in the Mail app? I can't fathom why both devices stopped working simultaneously. Very strange and extremely aggravating!