As August is nearly a year ago, we need much more details on how you have been taking care of him in the last 10 months. What cage size, basking temp, what do you feed him? do you have UVB? substrate? Have you gotten a fecal done on him? How much is he eating per feeding?
I do hope you mean you are feeding him twice a day, not twice a week. IF you are feeding him only twice a week, that is why he is still very small. Bearded dragons should be fed every day at least. Young bearded dragons need to be fed 2-3 times a day, reducing as they get older till once a day insects/greens available all day when they reach 8 months of age. After a year, 2-3 insect feedings a week or about 10% of their daily intake, with the rest being greens/veggies/fruits/etc.
Please give more information about your setup, feeding habits, what you are feeding, etc. This information will make it much easier to determine why your dragon isn't growing.
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PHLdyPayne