Dell Travel Mouse WM524 can't connect

My Dell Travel Mouse WM524 used to work fine until a day when i've disconnected it and from them I've never been able to reconnect it. 

I turn it on, then I push on poxer button for 2sec to put it on discovery mode but the blue LED won't blink. 

hence the device won't show on my computer. Other than that , I bet that the mouse is working fine.

I'm running Windows 10, I've already changed batteries, I've tried with other laptops.

Thank you for your help !