Magic Keyboard Backlight not working

Hi everyone, I recently purchased a magic keyboard to use with my 11inch iPad Pro 2020 and all features worked except the backlight which was annoying as I just couldn’t see what the issue was after many hours of searching for help on the net. Anyway Today I updated my software o the ipad to iOS 15.1 and by doing this the backlight problem on the magic keyboard was fixed Hooray! However after an hour of use I closed the keyboard and when I went back to use it a while after the same issue is now occurring where there is no backlight and in Settings-Genera-Keyboard the magic keyboard is not showing? This is really annoying as the keyboard does work for everything else but now my ipad is not recognising the keyboard and the backlight issue has reappeared. Does the keyboard need to be charged separately? Can it’s firmware be updated etc etc? Can anyone help please, thanks.