Can't take a screenshot in the app

I sometimes need to take a screenshot of an account transaction (eg; recently need to do one to prove to a company that their debit order had gone through) but have been blocked from doing so with "Can't take screenshot due to security policy". So, I went to App Settings in the menu and changed the "Allow Screenshot" button to "on" (and I could send you a screenshot evidencing this - if I could actually take one). Still can't do it and still get same response. Why not? Why bother to have a setting for this if your security policy doesn't allow it anyway? And, I posed this question online in the app in the "Talk to us" page but the Bot didn't understand it and gave me some generic response conveying this (not surprising given my experiences with Bots/AI of this sort). Here too, I could have taken a screenshot of the Bot's response, if I could actually take one, of course.