Keep numeric keyboard presented when minimizing app

When I enter transactions in another currency than my default one, I have to switch between Budget Flow and my bank’s app to enter the original currency amount and my default currency amount, but the keyboard is dismissed each time I go back into Budget Flow, so I have to tap on the text field I was editing again before I can enter the amounts. This slows me down a lot, especially when I have lots of transactions to enter in the app.