It's reassuring but worrying to know that this is common enough for it to be "a thing". This is probably the one single experience I have had in ALL the Asian countries I have experienced, and very often in the China Towns of Western cities. Waitresses and waiters unfailingly look straight through me at my kid or non Chinese/Japanese-speaking companion when I am speaking and somehow aurally blank my voice; but when it's time to pay, the bill/"check" comes straight to me.
It is pretty dehumanising to be reduced to a token ignoramus whose only function is that of a walking wallet. In Japan, I found Thais and other South East Asians bad for this. They would fail to hear anything out of my mouth and prefer to prod - in pidgin "nee hom ko" - my Japanese companion until s/he replied. On a few occasions, I had to do the ventriloquist dummy routine that you see in this video. On these same occasions, I instantly lost my invisibility shield when the bill/check came.