PRO Username: Nehhil 
Do you have active membership?: No 
Your knowledge about PRO: Basic Knowledge   
What have you done before the problem was there? 
I'm French sorry if grammar isn't that good   
I upped lvl 13 and Bulbasaur might learn Sleep Powder AND oxic Powder at the same time but I only learned Sleep powder (the game didn't told me to learn toxic powder), I didn't noticed but, after I beat Brock My Babasaur upped 2 lvls so he wanted to learn Take Down and when I learned him he learn toxic powder instead, same when he wanted to learn Razor Leef; he learned Take Down instead, same with other capacitys.   
What have you already tried to solve the problem? 
I think I solved it by refusing to learn another ability but I don't know if it happens with other Pokemons.   
Description and Message 
I didn't see that there was a description bloc x) I said everything in "What have you done before the problem was there?" bloc. Sry   
-Nehhil