Labels in volcano plot


I’ve followed the galaxy tutorial to create a volcano plot and to label the most significantly expressed genes. But some dots, even if they are significantly expressed stay unlabeled while some other dots which seem less significant are labeled. Like this :

( I mean there are many blue dots that need to be labeled before the other labeled red dots )

I’ve used DESeq2 and Annotate DESeq2/DEXSeq output tables. What could be the problem and how can I fix this?

Thank you!