What's harming my Sedum Purple Emperor?

What's harming my Sedum Purple Emperor?
The damaged one has been grown in pot since it was a cutting and is on my patio which gets the full sun in the afternoon.

This healthy one is grown in a rough area at the bottom of my garden and has been neglected really.

I have several green sedum in pots on my patio and they are fine.
Any help appreciated. Thanks
0
Posts
Thanks Verdun,
I wonder if it was the sun causing the problem. I'll remember to target the watering into the pot and not overhead in future.