Wind burn, too much sun, not enough water... probably a mix of all three!

MG's right - they like cool, dappled shade between 11 and 3 in the summer and a sheltered spot out of winds - they do need some sun for keeping their leaf colour though. This is a result of the heatwave, I'd imagine

Thank you, both. I have moved it to an area that gives it the conditions you recommend.

Hope it survives!

It's looking much healthier now, I will take a new pic and put it up. Thank you for your advice.