Geyser working incorectly / not following description

The unique weapon for the Zhen , the Geyser , doesn’t work as advertise .

9ea7bf83a3a7bf51faca4359c7d90307.png
https://gyazo.com/9ea7bf83a3a7bf51faca4359c7d90307

as stated in the description , it should “fire in short bursts”  , but it doesn’t 
6383be3ceedd63620ac8e7eda971cf14.png
https://gyazo.com/6383be3ceedd63620ac8e7eda971cf14

as seen above , it fire just like a assault railgun .