Hi Lee,
There’s nothing you need to do for this trick to work so I’m not sure as to why it’s only sometimes working for you. It might be that the keys are not on the same frames, but I can’t tell without seeing you try it and it not working.
By the way this “trick” works because it’s changing the handles to have both the same length and angle (flat). Then when you adjust them together they are changing their spacing in sync with each other. I hope that makes sense.
If you are still struggling with this you can try and record a screencast and then I’ll be able to ‘see’ what you mean.
You also don’t need to do this trick. You can manually adjust the handles which is great practice in itself.
This “trick” is just a hack I have found through experience.
