Haven't noticed any issues. I'm an Office 365 for Education business user. Can you think of any other change that happened right before you started to experience this? Update any Office 365 apps? Change your Office 365 password? Do you have 2 factor authentication enabled? Did you disable or change your iOS device unlock passcode/PIN?
I use the apps on both an iPad and an iPhone. You might want to try signing out of one of the problem apps and adding your account again.