New growth on yucca dying

My new yucca seems really happy in a sunny position right next to a floor to ceiling glass window, so much so it's sprouting new growth all over the place. The only problem is when that new growth starts growing the leaves curl up, go crispy at the edges and soon die. The plant as it was when I bought it all seems fine but the new growth just dies off. I've also notices that the new leaves carry like a white powdery substance on  their surface. I considered some kind of infestation but it doesn't look like anything I recognise as being like a bug infestation. Could it be fungi? I'm enclosing photos. Thanks so much for your advice!