The up and down arrow button on v-number-input do not repeat action when holding mouse button down

[jaaf]

Using the v-number-input in the playground of vuetify.com, when holding the left mouse button down on the arrow up or down spinner button, the increment or decrement action is repeated as long as I hold the mouse button. This is not the case in my app whith exactly the same code. It increments only once.

Example of code

<v-number-input label="test" control-variant="default"></v-number-input>

and this is the same whatever control-variant may be :stacked, split, etc.

What could explain this behaviour ?