No Siri invocation using LG HBS-750 and iPhone X...

My LG blue tooth headset invoked Siri on an iPhone 6s using the left button on the headset.

However, it does not seem to work well when paired with iPhone X. When headset is paired with iPhone X and left button is pressed, it activates Siri (As can be seen on the iPhone screen), but the microphone on the headset does not get activated and Siri times out.

Has anybody else experienced this or similar situation? If so, any remedies?

Thanks!