What caused Charmeleon to become so disobedient to Ash? Early in the series when Charmander evolves to Charmeleon, almost right away it begins to disobey Ash and refuse to listen to him. this continued to Charizard who would lounge around and blast Ash with a fire breath until he was frozen in ice during Ash's travels though the Orange Islands and Ash stayed up all night trying to melt the ice.

from what i remember Charmander willingly went with Ash when it's trainer abandoned it and he was about to die from the rain. if i followed the game logic i could assume that it was because Charmander's Level went too high in comparison to what badges Ash had however....


there was no signs of disobedience until after the evolution
the 8th badge of any region allows full control no matter the level however Charizard was still disobedient even after Ash got Kanto's Earth Badge.


not to mention that the level control ability of another regions badges would be made obsolete for someone like Ash who gets badges from other areas



So what caused Charmeleon to become so disobedient to Ash?
I found this interesting and helpful tidbit of info from an old PokeCommunity forum thread. It's not conclusive, but it is explanatory:


  I think of it as like Charmeleon was like a teenager. It had paid
  attention to Ash when it was young and naive, because it Ash showed it
  caring and love. However, when it got older, and learned more, it
  became cocky and saw Ash for what he was-- a rookie trainer that was
  still learning many of the basics. I think Charmeleon felt as if he
  didn't have any respect for Ash. When he started listening to Ash in
  the Orange Islands, it was after he saw how dedicated and serious Ash
  could be, even to something that was repeatedly rude and menacing to
  him. I think that when Charizard saw Ash doing that, he began to have
  some respect and admiration for the boy.
  
  Charizard may have been a 'plot device' to show pokemon that disobey,
  but it was important because it showed that not even Ash could 'wow'
  every pokemon with a couple days of friendship. It also was an
  indication of Ash maturing.


And here's another interesting viewpoint from an old question on Quora:


  Since Charmander was once rejected as weak he had gained an
  inferiority complex. He was always trying to prove himself. When he
  evolve into Charmeleon, he lost his fear and considering itself as
  proud. He gained self-pride and was considering itself as strong
  pokemon. Thus he was arrogant, and didn't listened Ash's orders. Later
  it evolved into a Charizard to prove its strength in front of a
  Aerodactyl. Charizard retained his disobedience to Ash as of
  Charmeleon. However, when Ash saved him after being frozen by Tad's
  Poliwrath's Ice Beam, Charizard's loyalty to Ash returned in full
  force; the best part of Charmander's pre-evolved personality was back.
  So the arrogance and disobedience that Charizard (or Charmeleon) was
  beacause he was boastful of his immense power.