Ok, so you did not make it clear what the bug was.
What you are saying is that the effect should be once per turn but you could only use it once per duel.
This is not a bug from that replay as the effect states that "While this card has a "Number" monster attached to it as an Xyz Material, it gains this effect." You detached the "Number" card from it to activate its effect the first time, so once it has lost a "Number" card as the Xyz material it loses its effect and can no longer use it.
To use its effect multiple times you need to detach the materials that are not a "Number" card as costs for its effect first so that it still has its effect.
Edited by user
| Reason: Not specified