It happens that dragons grow very quickly and by 6 months they become an adult. In this case, correction of their insects is required and here good advice can be given by
@AHBD
Figgs, how many insects are you feeding Syrax per day and what type ? Beardies can grow very quickly when fed too much and this can and often does hurt them in the long run. Their liver , kidneys and other organs develop problems. But there are different amounts suggested depending on the size of the beardie and the type + size of insects.Your dragon is young but already 17" long so a sub adult and can be fed insects just 2-3 X a week and greens on the other days.
For simplicities sake we'll use crickets or dubias as an example. We'll say " approximately" so there's wiggle room to use a couple more or less than these suggestions . If someone is feeding a 17-18" beardie 15 large crickets at a time it would be too many. But if it was 15 medium , it would probably be fine. Of course having the larger crickets you could use 6-7 large ones 2 X a week and greens on the other days. Using larger ones would save you money because you would be buying + using less.
Dubias are bigger + meatier so you would never even feed them 6-7 large dubias, it would be maybe 3-4 of them 2 times a week along with greens. Some beardies seem to have a hard time even chewing up a very large dubia so it might be best to always go with ones that are not quite adult.
BSFL are very small for a larger beardie even if you get the large size larva so you could use probably 10-12 large at a time, even a few more but not too many and this would be expensive.
Superworms can be fed as one meal a week but only 3-5 at a time since they aren't quite as nutritious.
Those are the main feeder insects used so those are the ones I mentioned.