Yes, I have had the same problem with two wireless keyboards that previously worked fine with Raspbmc and Openelec. I used the keymap in this thread to get them back in OSMC. I customised it but you can try as is but most stuff is not needed, otherwise generate your own.
https://discourse.osmc.tv/t/remote-suggestions-for-a-pi-2/
Info on modifying key maps here:
http://kodi.wiki/view/HOW-TO:Modify_keyboard.xml