iOS app won't open again after leaving application

iOS app won't open again after leaving application

It seems that since the ios 10 update I'm only able to use the app once - if I press the home button or switch to another app, I just get the "out of focus" screen when I try to use the app again. I have to force close the zoho app and restart to be able to use it a second time. This gets very tedious and time consuming when I'm trying to use the calculator or verify totals from other sources to input into the app.