To answer your question from an operator's perspective, these vehicles are operated by a city contractor. They have not experienced any such issues.
To clarify, we're using compressed natural gas and not liquefied natural gas, so some of the problems you are asking about are with respect to LNG and not CNG.
I can't answer your question relative to LNG as we don't have that experience here at the City of Surrey. We don't have LNG-operated vehicles.