The word “enchanté” is being said in a meaning "Nice to meet you", when you met new person first time.
Is it appropriate to say “enchanté” in a meaning "I am glad to see you again" to a person, that you already know?
No, it would be like saying "nice to meet you" again. [to meet you] is always implied in enchanté.
If you want to express the pleasure of meeting again, it has to be explicit:
Enchanté de te revoir (sounds a bit weird)
Content de te revoir
Un plaisir de te revoir (better)