Sorry, but that doesn't help either. I think it has something to do with my LogiTech Slim Folio Keyboard, which is weird because I've been using it for close to 2 years now and never had a problem with it.
I used to be able to use the Caps Lock button to switch between emoticon and other languages' keyboards, but now it doesn't. The settings for 'Hardware Keyboard' in Settings>General>Keyboard>Hardware Keyboard>Modifier Keys, originally set my Caps Lock button as the World button (this was the default when I bought my iPad and Slim Folio Keyboard).
When I started having the problem mentioned at the start of this discussion, I have tried all your suggestions and more and none of them worked.
But after some experimentation, I found out that for some reason, it had changed to function as 'Caps Lock'. So, when I accidentally used the button as 'Caps Lock' it messed up (and still does) my range of keyboard options (i.e. Emoticons, Japanese, etc.), even for the on screen keyboard of my iPad.
What I have done now to avoid using the Caps Lock function is to change the settings in 'Modifier Keys' after resetting/restarting my iPad so that the Caps Lock button doesn't do anything now and my onscreen keyboard has gone back to normal... although I would like it if I could use my Logitech Slim Folio Keyboard like before. I'm not sure if this problem was due to an update to the iPadOS or not :s
However, thank you everyone for chipping in with suggested solutions :) I appreciate it.
