You can use Logitech Unifying Software to reconnect your MX Vertical mouse. 

NOTE: If you don’t have the software, you can by clicking on the Download link in the left menu panel.

After installing the Unifying software, use the following steps to connect your device to a new Unifying receiver:

1. Turn the MX Vertical on and make sure the charging cable is unplugged.
2. Press the Easy-Switch button to select the channel you want to connect to.
3. Press and hold the button for three seconds (until the LED starts to blink rapidly) to start discovery mode.
4. Open the Logitech Unifying Software and follow the on-screen instructions to connect your device. When prompted, plug the Unifying receiver into a working USB-A port.