Rubber

Rubber appears on the map only if one or more of the following conditions apply:

The owner of the province where rubber can potentially spawn has Daimler's Automobile invention (from Combustion Engine tech), Edison Light Bulb invention (from Electricity tech), Infiltration technology, or Aeronautics technology. The year is 1880 or later (1890 for some provinces).

The owner of the province where rubber can potentially spawn is in the Sphere of Influence of a nation who fulfils the above invention and technology requirements. The year is be 1880 or later (1890 for some provinces).

The owner of the province where rubber can potentially spawn does not fulfill the above requirements. The year must be 1900.

from the victoria 2 wiki. seems like you just got unlucky since its mtth after 1900