My Beats flex cannot connect to different devices without restarting. How can I fix?

When I disconnect my Beats flex from a device A and try to connect to another device B, the Beats flex cannot be connected. When the Beats flex is restarted pressing power button and volume down button for a few seconds, the Beats flex can connect to any device but if I choose to connect device B, when I want to connect to device A, I need to restart the Beats flex again.