They worked with an incorrect radius of the earth, so they didn't stretch the known landmass. That's the reason they thought they would find a way to india in the east.
It's unlikely Columbus saw this globe before he sailed to America. It was finished around the same time he arrived.
Better look at the globe: https://globus1492.gnm.de/
Bild 4 und 5 sind zeitlich vertauscht. Das 4. stellt schätze ich ca das 12. Jahrhundert da, das 5. dürfte aus einer Ausgabe des Tacuinum sanitatis aus dem 15. Jahrhundert sein.