Rulings Difference Between Master Duel and Other Formats? Sanguine Swamp and Imperial Custom

Be warned, this is not a beginners question.
So I have been playing around with some truly scummy tactics after a chance discovery of a certain card interactions involving Imperial Custom. It first started after I noticed, that if you played Imperial Custom with Vanity's Emptiness, even if a card is set to the graveyard, as long as Imperial Custom was on the Field, Vanity's Emptiness would stay. After Vanity's got rightfully banned in master duel a question then rose in my brain regarding other continuous trap cards I could use this interaction with. Sanguine Swamp seemed perfect for the plan I was trying to hatch, an unbreakable board state, where all the opponent could do is sit down and get burned.

The make up of my unbreakable board is a very inconsistent one, one that requires too much stalling to be viable, but I wanted to make it regardless because it was funny to me (I am a sadist).
It consists of 5 Continuous traps and 1 Continuous spell.
Skill Drain, Sanguine Swamp, Imperial Custom, Anti-Spell Fragrance, Abyss Stungray, and Cauldron of the Old Man
It didn't work, but not for the reason I expected.

For Reference, the effect of Sanguine Swamp is thus " If you control any other Spell or Trap Cards, destroy this card. Face-down Spell and Trap Cards cannot be activated. Destroy this card during your 2nd Standby Phase after activation. "

Additionally, Imperial Custom's effect is " Face-up Continuous Traps cannot be destroyed by battle or card effect, except "Imperial Custom". You can only control 1 "Imperial Custom". "

The interaction should be obvious, but I wanted to check if it worked. So I booted up Omega, and tested it under OCG and TCG, and under both rulings, my plan, while inconstant, actually worked! Sanguine Swamp would stay on the field regardless of either effect as long as Imperial Custom was there too. However, when I tried to implement it in Master Duel, it did not. The reason was the "Destroy this card during your 2nd Standby Phase" effect resolving when I thought it shouldn't have. I made sure to go well past that turn timer when I tested the interaction in Omega, but for some reason, it just didn't work in Master Duel.

Does anyone know why this happened?