In original version, the Winx got Charmix power during the last episodes of season 2. However, as of season 3, Charmix was never used or mentioned making it unknown whether they still have it.
Even though the Winx had new everyday outfits in season 3, 4Kids version kept using shots with original season 1 outfits during transformation sequences.
The Winx graduated from Alfea in the first movie and started working there as teachers in season 4, but as of season 5, they appear as Alfea students again.
It was never explained why Diaspro was allowed on Eraklyon in season 5 after she was banned from it in season 3.
In original version of Season 3, in recreated version of Musa's Magic Winx transformation, Musa's wings disappear in the last couple of frames.
Flora's wings are missing in the last shot of her original Magic Winx transformation.
In season 3, Aisha was blind when she first got her Echantix transformation so her eyes were white during the whole sequence. Later in the season, when she restored her sight, her eyes were still white for a couple of frames during her transformation.
Despite the fact that Enchantix was said to be the final fairy form in season 3, the Winx continued achieving many new transformations in the following seasons.