I have noticed that when using full screen navigation gestures with no hints and having Gboard open, results in a space (or other key) being accidentally pressed when using the swipe gestures. It doesn't matter which app is open, but the only way around this is to enable hints. My preference is to not use hints, because I like a full screen experience. I have One Handed Operation + active as a workaround gesture, but it's not quite as intuitive as swiping up from the bottom center to go home. While this is a relatively minor thing, having to erase a space on every text message I swipe away from on the next message I send is not preferred.
I am hoping I am not alone in noticing this bug that has occurred with Gboard for the last two iterations of One UI. In One UI 3.0, installing Good Lock was a fix for this. I submitted a report during Beta 1 and am hoping there's a way this can be fixed.
Setting the gesture sensitivity to high does not fix this, unfortunately. I have noticed Beta 2 is a lot more stable (only a few reboots) but with much higher battery drain.
I appreciate the Samsung devs and QA team working hard and listening to us as we navigate this process together.
I've had this issue as well since the fullscreen navigation gestures have been on Android. I always have the hint bar turned on. I use Google keyboard