Are these stress marks?!

[Lexylexyy]

I couldn’t tell! He’s eating healthy, pooping regularly, active etc! Also when I got
Him he had this pattern!

 

[AHBD]

Yes, those are a common pattern esp. on younger dragons but the term " stress marks " can be misleading, they can be there for no real reason and do not indicate a problem. Most young dragons show those at times, older dragons not so often.