Salix dwarf tree

Hi All, hope all your gardens are surviving. I have a problem with a Salix dwarf tree/shrub which i need some help with.
Firstly, the plant has been in the garden for a few years and has been growing well with no problems. This year though it started the season with very few catkin type blooms compared to previous years when there were hundreds.
Secondly, the plant is now showing a lot of brown leaves which are curling up. I have opened these up and cannot see any signs of insects or mold or anything else that might suggest an infection of some sort.
The ground is normal but probably has some chalk influence, all of my garden is this kind of soil. The plant is located on a sloping area of the garden so probably gets good drainage and water from surrounding areas.
Any help or suggestions on what the problem might be would be very helpful indeed, thanks.
Not sure if pigeons landing on it might have brought some disease with them ?.
Thanks John
Photo's attached.