Q.Rhododendron flowers
The trumpets will not open and have now started to fall off. This bush was fine last year and had even more potential flowers this year.

The lack of leaves and flowering issues may indicate a fungal issue with your plant.
It is often call dieback.
These links have more information.
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendrons-in-containers.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendron-care.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/issues-with-rhododendrons.htm