The next time you see a bunny in the beam ideally a squatter.
Stand about 30ft off.
And give his slip a few short tugs nothing hard just a few inches.
And at the same time ask him the same thing when he's looking for his lost ball or tug in the grass.
But say it with a bit of excitement to your voice.ie were is it etc. and only loud enough for him to hear it and not the bunny.
Do that maybe 5 times untill you see he's looking keen.
Then walk slowly towards the bunny every second or 2 a little tug and an excited quiet voice from you.
Let him have the run.