Looks exactly like Phytophthora, a soil borne fungus that causes wilt and death. Commonly, this disease is called Rhododendron (or Azalea) Wilt.

Lots of moisture exacerbates the problem.

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I doubt if it is the variety. PJM is tolerant of cold, heat, sun, and shade. It could be the soil has poor drainage which is death to most any rhododendron. There are a number of different causes for curled leaves:

1) In the heat of the day, most rhodies will curl the leaves in a defensive manner to protect the stomata from dessication. Do not mistake the normal wilting action caused by extreme heat or cold as an indication of a problem. It is normal and will go away when milder temperatures return. Only water when necessary and in hot weather always err on the dry side, but don't hesitate to water plants that look wilted in the morning. In hot weather it is normal for rhododendrons to look slightly wilted in the heat of the day, but if they look wilted in the morning, then they are too dry. Watering may be needed in winter or summer.

2) If the root ball is not thoroughly soaked when planting, it will be dry as a bone inside and never accept moisture. This is especially true of field grown plants. Rhododendron guru Harold Greer noted: "Quite often a plant will get completely dry and then no matter how much water you apply, the rootball will just keep shedding it. The top of the soil may seem wet, and the soil around the plant may even be very wet, but the actual rootball of the plant is bone dry. This is especially true for newly planted rhododendrons, and it is the major reason for failure, or at least less than great success with that new plant. It is hard to believe that a plant can be within mere inches of a sprinkler that has been running for hours and still be dry, yet it can be SO TRUE!"

3) Phytophthora Dieback, Phytophthora cactorum: The fungus Phytophthora causes one of the most common disease problems in the landscape for rhododendrons and azaleas. This fungus is a "water mold," and thrives in poorly drained or wet conditions. A wilted plant is usually the first sign of trouble. Rhododendron leaves will curl inward and droop. Drought can cause similar symptoms. Roots of affected plants appear soggy or blackened, and the outer portion of the root easily pulls away from the inner portion.. Crown rot causes the lower portions of the stem to have a brown discoloration of the wood near the soil line. This disease is favored in poorly drained areas or when plants are set too deeply. Plants may remain without symptoms until further stressed from drought or flooding.. Azaleas. Resistant: R. sanctum, R. simsii (Indian azalea), R. yedoense var. poukhanense (Korean azalea), 'Corrine,' 'Fakir,' 'Fred Cochran,' 'Glacier,' 'Hampton Beauty,' 'Higasa,' 'Merlin,' 'Polar Sea,' 'Rose Greeley'. Moderately resistant: 'Alaska,' 'Chimes,' 'Eikan,' 'Jan Cochran,' 'Morning Glow,' 'New White,' 'Pink Gumpo,' 'Pink Supreme,' 'Rachel Cunningham,' 'Red Wing,' 'Shinkigen,' 'Sweetheart Supreme'. Rhododendrons. Resistant: 'Caroline,' 'Martha Isaacson,' 'Pink Trumpet,' 'Prof. Hugo de Vries,' 'Red Head,' R. davidsonianum, R. delavayi, R. glomerulatum, R. hyperythrum, R. lapponicum, R. occidentale, R. poukhanense, R. pseudochrysanthum, R. quinquefolium and R. websterianum. Do not set new plants any deeper than the original soil level. Planting in raised beds is suggested. Firm the soil slightly at the base of the planting hole to prevent the plant from settling into the bed. Do not plant azalea and rhododendron plants into sites where plants have previously died from root rot. Even resistant plants may succumb under these conditions. The fungus survives in the soil and cannot be eradicated once an area is infected.

4) Phytophthora Root Rot, Phytophthora cinnamomi: This is a serious, widespread and difficult-to-control fungus disease affecting a wide range of plants . The symptoms of Phytophthora root rot vary with the cultivar. Some cultivars fail to grow or grow very slowly with pale green foliage and may die after several years. Others suddenly wilt and die within a few weeks. Roots are reddish-brown, brittle and often limited to the upper portion of the media in a container or very close to the soil surface (upper 2 inches). The reddish-brown discoloration advances to the larger roots and eventually to the lower part of the main stem. Phytophthora root rot is favored by high soil moisture and warm soil temperatures. The disease does not occur as frequently and may not be as severe on well-drained sandy soils as in heavy clays or poorly drained soils, etc. The disease is common and severe in areas where run-off water, rainwater from roofs, etc. collects around plant roots. Setting woody plants deeper than the soil level in the nursery or container, over-watering plants, or long periods of heavy rain also favor disease develop especially in shallow soils with underlying rock or compacted hard pans. Phytophthora root rot must be prevented as chemicals are often ineffective in controlling this disease after aboveground symptoms appear.