Yes there's a problem, if you're not in Ireland Wales or Scotland or the north generally - drought is the most likely explanation. Water well and keep watered, provided you can see no obvious signs of infestation or disease.

Trim off the blackened shoots and give it some water. Has it been planted for long? If it is an established plant, then something could be restricting the flow of sap to the top of the plant or the roots may have been attacked by insects or fungus. Check that there are no tight ties/twine etc throttling it first.