Using TMs

[DarkMeow]

I bought Thunderpunch and used it on one of my pokemon, Raichu.
The TM disappeared and my pokemon didn't learn it.
What caused him to not learn it?

[ShadowLera]

Although I don't have an answer, I can say it has happened to me a few times too, except with the Surf HM.  Also something similar happened yesterday when I taught a Scyther Hyper Beam, and it worked, but somehow my Pikachu learned it too.  Some unknown bug... Maybe Sirus has a better idea of the problem.

[DarkMeow]

It's happened to me with Surf, as well.
I'm sure it goes for all of the TMs.

[Sirus]

I know why this happens - it occurs when you have clones of that Pokemon in your team. You'll try to teach them the attack but the code will select their clone instead and send them the popup about learning an attack. When a clone gets a popup it automatically selects the default options, so I imagine it would say "Yes" and replace the first attack of that Pokemon. Of course, that doesn't help YOU at all...

[DarkMeow]

Thank you for answering my question. :3

For trainers who are going to teach their pokemon a TM:
Check if there are clones in your party.
Click Set Up Pokemon Team under commands.
That will give you a list of your pokemon.
If there are duplicates of a pokemon, I suggest not teaching that pokemon a TM so you don't lose any money.