All too common. People who suffer this continuously seem to have specifically laryngopharyngeal reflux disease (LPRD), which is reflux affecting mainly the throat/mouth, little of any other typical "acid-reflux" (gastroesophageal reflux, GERD) symptoms, and are better lying down asleep than being awake (reverse of GERD).

In any case, these symptoms are frequently listed under GERD symptoms.

I have an incessantly warm throat, which is often scratchy or "burning" or even sore. Also I have the sensation of lots of phlegm - which I've always had, as a sinus sufferer, but this is different - lower down in my throat than normal, and more liquidy. So yes, I clear my throat alot because of the "phlegm".