Rhododendrons: Sickly Roseum Elegans Rhododendron

I am new here and hope someone can lend me some assistance in trying to figure out what exactly is wrong with my Rhodo...

As you can see in this first image, I have a Nova Zembia Rhododendron that is growing very well on the right side of the picture, and a sickly Roseum Elegans Rhododendron on the left.



Here is a closer shot to it, you can see that the leaves towards the middle are brown, unhealthy.


Below is an image of the color changing in the stem.


And some closer images of the leaves etc.



The brick in the image faces the North, the sickly Rhododendron is not blocked by anything on the East and as you can see gets that sunlight at 6pm. Both Rhododendrons were planted at the same time, same flower bed, same dirt etc.

Thank you in advance, let me know if any more data is needed.