The same applies to the Rafale, it took me two flights to get a good blend between the incidence on the Canard and a match to the Elevons.
Now it flys beautifully.
I use lots of canard movement with gear down to aid take off's & landing's but small amounts for flying using the retract switch to put movement on & off.

That video looked like there was a lot of down mixed in to start or a major component failure.
Arn't the canards on the Lavi fixed?

All the best, and better luck next flight,
John C