I’m on a Galaxy S7, but if you mean this app, then the flick keyboard doesn’t work for me, either, and I actually don’t remember it ever doing so. My flick keyboard reverts to being a tap-through type when I use it to input readings.
That app’s also unfortunately no longer being updated, so if the flick functionality is important, you may want to see if the the other android app allows the flick keyboard input or using WK in mobile form, as it does allow the flick keyboard to work properly, at least from my own experience.