You might just need to reshape the end of your spring again. Check to see if it’s lost it’s sharp edge where it catches on the barrel hook. You can to this with small round file tilted at an angle. If the spring looks good then you may need to file a bit of an undercut on the barrel hook (pin) so it catches the spring.
Please let us know what you find out Chaplin37,
Good luck…you’ve almost got it!!!!!