Rank-Up Stones can't be used back-to-back?

2Crows

I'm bringing up a 5* to use in Act 6.

Used a 2 -> 3 stone, maxed level, and tried to use a 3 -> 4 stone, but not working.

Is this as designed, or a bug?

Thanks.

Furrymoosen

We might need a little more info to help you here. You should have no issue using them unless:
The 3>4 is class specific and doesn't match the class you're using;

The 3>4 is a saga RUG and the champion you're trying to rank doesn't qualify;

The 3>4 is a generic from a back issues quest and is only usable on champs from specific years and the champ you want to rank is too new;

You're out of gold.