Kingdom Hearts II Leveling up Limit Form?

I just concluded the second trip to Twilight Town and the first one into Space Paranoids, thus granting me access to both Limit and Master form. This is the first time I have played KH II FM (First time ever having access to Limit Form).

Not wanting to wait until the endgame to max all my forms from level 1-max, I have been trying to level all forms up as the level cap is raised. However, Limit Form is giving me trouble for reasons I don't quite understand.

I have googled the matter, and it appears to level the form one must use one of the limits from the shortcut bar. Then, when prompted to continue the combo with the triangle button, do so to earn 1 exp.

Trouble is, I always see the triangle prompt pop up, but it is always grayed out and non-selectable for some reason. Not being able to finish the combo means no experience for me.

Does anyone know what I am doing wrong? I have leveled both Valor and Wisdom to level 6 in Agrahbah, returning to the peddler's shop when I need to use the world map to preserve the drive gauge. I am about level 33. Any insight would be greatly appreciated. ​

 

I just was coming back here to proclaim my foolishness. I was indeed not letting go of the L1 button once I initiated a command. Not a hard form to level after all. Thank you very much! ​