Confirmed Sanctum Prelate did not stop a non-creature spell with {X} in the cost as it was cast with the named total mana value

[Mikail]

Sanctum Prelate did not stop a non-creature spell with {X} in the cost from being cast with the named total mana value

1. Sanctum Prelate was on the battlefield naming mana value 4
2. Opponent cast March of Otherworldly Light targeting the Sanctum Prelate with X = 3, total mana value 4 (notably no cards were exiled to overpay for the cost)
3. The spell was cast and resolved, exiling the Prelate

I suspect that the Sanctum Prelate interaction with spells with X in their mana cost is not working as expected, as it was mentioned now working with different such spells by other players.

Example game with the bug:
Game 2, Modern League #7046
Match ID: #256195926
Game ID: #827979714

Video reference:

Rules reference:

For spells with {X} in their mana costs, use the value chosen for X to determine if the spell's mana value is the chosen number.