Oscillator circuit with a Negistor
This Esaki oscillator relies on some undocumented properties of the 2N2222A transistor, namely that the 2N2222A will have a negative resistor behavior under certain conditions.

See the first plot in the article from your link, note how the current decreases while the voltage increases. This behavior is not mentioned in the datasheets I found so that leads me to conclude that this behavior is not guaranteed by the manufacturer.

So what I see as a possibility is that some 2N2222A transistors might have this behavior and some don't or have a different behavior. Although any 2N2222A should behave the same, when they originate from different manufacturers, there's no guarantee, especially for undocumented behavior.

So what I would do if I were you is determine if your 2N2222A really shows the negative resistance behavior by measuring I(V) (current as function of voltage) of your transistor. It it doesn't show this behavior then your oscillator can never work with this particular transistor.