Alternate set of weapon skills not working when using left trigger

Not sure why but when I try to use the 2nd set of 3 attacks on weapon bar its red and doesn't work. Like I hold down left trigger and can't use them. In tutorial it worked but not in regular game. I've tried swapping the skills around. Then only the front 3 work. I have to be missing something simple.

Are you using skills that are for that specific weapon?

Same with techniques. if you are using a class that cannot use them.