Some Phenos just start showing endof life hermaphrodite traits like throwing nanners sooner/more likely than others.
If you would breed that phenotype with another that does the same then you are likely going to get that trait into your filials.
That said though, if its a fast flowering strain, it would make sense that it would display the hermaphrodite traits sooner than other plants, since its reaching its end of lie faster.
Also, mind you that when you see a nanner, everything around it is polinated immedietly, theres no "fixing" it. wherever you found those nanner you will have seeds if you allow it to grow.