What's up with my hydrangea?

[Etceteraaah]

I recently bought a new hydrangea (bluebird). It looked great for the first few weeks but this week I've noticed it looking a bit peaky. It's developed spots on its leaves and its newer leaves are slightly deformed in shape. What is causing this?

Could it be soil acidity?

Hydrangeas like to be kept damp and in semi shade, maybe not enough water or too much sunlight.

@RoseRedRoseBlue

Could it be soil acidity?

It came looking very purple and from looking online it suggests that this could be caused by the soil ph being wrong for the hydrangea. I'm wondering if the supplier had fed it that stuff to make the hydrangea blue and that's caused the imbalance. I will feed it hydrangea recommended feed and see if that perks it up.

@Beebumble2

Hydrangeas like to be kept damp and in semi shade, maybe not enough water or too much sunlight.

It's in the perfect spot in our garden for hydrangeas so I don't think water or sun/shade is the issue but thank you for the suggestion.