Hi SamG1,
Open Terminal (/Applications/Utilities/Terminal)
- Type in the following command and hit 'Enter':
defaults write 'com.parallels.Parallels Desktop' 'HID Host Hook.CAPSLOCK Sync' -bool false
- This command will disable automatic CapsLock synchronization between Host OS and Guest OS and will allow them to have different capslock states.
- Also try to reinstall Parallels Tools and check if it works!