To unpair a module, it must be visible in the Nearby Devices tab.
If this is not the case, be sure to check the supply voltage of the module.If it is a push button interface, you should definitely check this link:
Pushbutton not visible between nearby devices.
If you cannot disconnect the module, check these settings (Allow unpair/ Allow flick unpair/ Allow Utility unpair). These must be enabled so that the module can be disconnected.