[Q] Keyboard Doesn't Close After Every Text topic

I recently face a keyboard issue that anytime i insert several emoji on Whatsapp or write a text, send it and press the home button or back button, the keyboard doesnt go away and stays at the screen for like 60 seconds, which doesnt let me use the other stuff like if i returned to the home screen i lose the bottom half untill the keyboard finally goes away. I already tried factory reset, reinstall Xperia Keyboard's updates and none of them didn't work. But other keyboards like SwiftKey doesnt do this. Could anyone help me about this situation? I will be very glad if i find anyone who can fix this :)