What do you expect when a government agency calculates inflation, while other government agencies has liabilities pegged to inflation (Social security, TIPS)?

Sure, they're different agencies, but that doesn't matter in the slightest. It's like two departments in one company.

According to Shadowstats, which calculates inflation using the 1990-based CPI methods, inflation currently is at 4.5% per year. http://www.shadowstats.com/alternate_data/inflation-charts