'Inside Defense' website:

The Navy recently directed Boeing to provide a time line for when the company can retrofit the T-45C Goshawk with a liquid oxygen system, Inside the Navy has learned. The service is conducting a comprehensive review of the physiological episodes pilots have reported for both the T-45 and F/A-18. Physiological episodes occur when aircrew experience a decrease in performance due to cabin pressure fluctuations, air contamination or other factors in the flight environment."

Don't know if this is accurate, just FWIW.