Buggy front wheel bounce?

[seaside]

I was out yesterday and was going faster than I have done before as I am an occasional buggier, and the front wheel of my Peter Lynn comp st, started bouncing around that much that I had to de-power the kite to stay safe.

at first I thought it was the sand, but then realised it was due to speed, how can this be stopped or should i look for a better buggy as I now wish to go faster but do not want this to happen again and spoil my fun

Cheers