Acer disease? Or overwatering/overexposure....?

Hello! This is my first post, I'm new to this site, and I'm also a novice gardener.
I inherited a beautiful Acer from my Auntie, who had cared for it very well.
The Acer was replanted in my garden and all was well until recently. It was previously sheltered by a large conifer, which has now been removed leaving my Acer open to direct sunlight. I've attached a photo of the wilting and white damage to the leaves. Is this due to overexposure, overwatering (I've been watering the area a lot recently) or is it a disease that I can do something about? Advice gratefully received.

 

It kinda looks like it’s had water on the leaves during a sunny spell? They do need a bit of shelter from the sun and wind.

 

It could possibly be wind scorch, now it's lost the protection of the conifer it may be over exposed.