Rhododendrons: Fragrant Rhododendron not flowering properly

Hi there,
Wondering if anyone can help me with a problem I have with our fragrant Rhododendron. We have had it 3 years and the first year when it came home from the nursery it flowered beautifully. Since then it has grown well, the leaves look healthy but when the flowers start to open they don't form into proper flowers they just turn into 3 clumpy buds (photos attached). And this year half the plant didn't even have flowers just shoots or leaves coming out. I'm not very garden savvy and don't have all the terminology but I do have 3 photos. If anyone has any advice I would love to hear from you!
Many thanks!

 

These buds will not open up subsequently? So far it looks normal, variation in production from one year to the next is also normal. Flowers come on the ends of the thickest, strongest shoots. After a shoot terminal flowers smaller shoots come from below to continue on. These are often not big enough to flower the following year. So, theoretically a section of branch could flower every other year only or sometimes have a two-year gap between flowering, depending on how soon the shoot(s) got big enough to bud again.

 

Thanks for replying. Yes you could be right. Maybe I'm panicking too soon. It's just that last year it got this far and that's as far as it got. We had a whole bush full of half opened flowers. All the other rhododendrons we have seem to progress quicker from bud to flower than this one has done so far. And we have another purple one (much bigger) which did the same thing for the last 2 years (but it looks sick....Brown patches on the leaves). Anyway, I don't really mind about the purple one but I was really hoping for fabulous fragrant rhododendron flowers this year. Fingers crossed that they are still coming!!

 

Brown patches on the leaves might be mildew. Look more closely, for a moldy or dusty appearance on the undersides of the leaves.