the dropdown beside "blocks" not working properly

[sanket0211]

Dear developer,
First when I saw the the dropdown arrow, I thought it would be hovering effect. Then when the dropdown did not occur, i clicked once on the arrow. On clicking once, the options appeared once and then disappeared. I thought I had clicked more than once, so I retried. But same happened. Then I realized that we are suppose to double click.
This is like not good for user interface. Can be improved.
Thank you.