Ios 11

Help! I have an issue where drag and drop multitasking on ios 11 is not fully affective on my ipad mini 2nd gen. Only one window/tab (the drag and dropped tab) is active at a time. The other (original) tab turns dark and i have to exit the drag and drop tab to use the other one. I know both screens are supposed to be active but mine isnt. Is there a reason or a fix? Thanks.