I have a couple sabara in the ground also.
What I noticed with all my jabos is that as they get bigger and older
they flower and set fruit more and more. One of my sabaras is fruiting
several times a year now and so far all the fruit have one very small seed.
This is the third year I have gotten fruit and it fruited 3-4 times so far
this year. My other tree flowered in the middle of rainy season for the first
time and none of the fruit set. Be patient