Bug report for "Ral, Crackling Wit" when using split card instants or sorceries

The emblem given by "Ral, crackling wit" is supposed to give all instants and sorceries you cast storm.
However, when casting a split card like "Insult // Injury", it seems that the game does not apply the storm ability to either side of the split card, despite being added in the visual overlay:

When either spell of the split card is cast, however, there is no trigger for the storm ability that goes on the stack:

Reproduce the issue by using Ral, Crackling Wit with the split card Insult // Injury, then trace how the emblem applies to each spell. Done means casting either side creates the expected storm trigger on the stack, rather than only showing the ability in the visual overlay.

Written by the indexing model from the issue text.