See Match #242906651, Game #774928170.
In this game, I had a graveyard with roughly 12 cards in it, and my opponent had 2. I had a Florian, Voldaren Scion trigger for zero, and it shuffled both of our graveyards into our library.
Strangely, I had had the Florian out for several turns, triggering for zero multiple times, and it was the third or fourth trigger where this happened.

Upkeep, Hapatra, Vizier of Poisons was in play.
Main, played God Pharoah's Gift
Played Hapatra, Vizier of Poisons sacrificing it
Beginning of Combat, God Pharoah's gift targets Hapatra, Vizier of Poisons
Token shows Summoning sickness, sacrifice 2/2 card
Token still showed Summoning Sickness, could not attack

Pia's Revolution "Whenever a nontoken artifact is put into your graveyard from the battlefield, return that card to your hand unless target opponent has Pia's Revolution deal 3 damage to them."

1. Nontoken Artifact goes to the graveyard
2. Pia's Revolution triggers
3. Opp is given choice between paying 0 or giving me the card back

Problem: Opp's choice should be take 3 damage or give me the card back rather than paying 0 mana.

Leyline Tyrant mana ability is bugged. I had 5 mana in the pool, when oponent killed tyrant. I wanted to pay 5 and hit my oponent, but instead 11 mana was counted?! You have to investigate that.

Scythe of the Wretched triggers don't work properly.

Steps:
1. cast scythe of the wretched. do not equip it to anything
2. cast a kill spell on an opponents creature

current results: scythe of the wretched triggers returning the creature and attaching scythe.
expected results: scythe should not trigger as there was no equipped creature responsible for the kill

Heres some video of the bug happening. Fast forward to 21:30 https://www.youtube.com/watch?v=vu0J6QmS4nM

I controlled Dress Down and cast an Uro. His draw ability triggered, but his Sacrifice ability didn't (how it should be).

I tried to use its ability during a slow and grindy match , mtgo was sluggish, but it sacced to itself. That is a bug, it should only allow to sacrifice another creature as i intended anyways.
So it sacrificed my creature that says , sacrifice "another" creature. Itself should not happen since its not a legal game process.

i played Angel's Grace off a Duathi Voidwalker. my opponent then cast Thassa's Oracle, and was able to win.

Cast a spell that you do not have enough mana to resolve
Begin paying the mana cost for the spell, using a Millikin
Try to cancel casting the spell

With following the reproduction steps, you will end up in a state where you cannot complete casting the spell and you also cannot cancel casting the spell. The only way to proceed with our match was for me to concede the game.

Kaya's ghostform is non functional, every time my commander dies it stays in the graveyard when it is meant to be returned with kaya's ghostform, card is completely non functional

Pauper: I discard Bartered Cow using Tortured Existence or Faithless Looting. Bartered Cow says whenever it dies or is discarded, create a food. Unfortunately discarding Bartered Cow does not create the food token. This triggered ability does work when Bartered Cow dies but not when it is discarded based on my limited testing using Tortured Existence and Faithless Looting.

Thanks for your time.

I was not able to suspend a card if I had cast another spell while curse of exhaustion was on the battlefield. In other words, I was not able to pay the alternate suspend cost to put the card into exile even though suspending a card doesn't count as casting a card and doesn't use the stack.

There seems to be a bug in the current Yuriko.
One library top card has been lost after reveal.

1. Attack with Kitesail Skirmisher.
2. Trigger goes on the stack to target a creature that the attacked player controls instead of a creature attacking that player.
3. Actual: It gives the attacked player's creature flying.
4. Expected: Kitesail Skirmisher's trigger should only target a creature attacking a player, not a creature controlled by attacked player.

Op blocked with skyclave appartion and i did not get a token when 4 cmc creature was exiled.

I played a Swarm Shambler card to copy the permanent spell with Lithoform Engine, priority was skipped I was with control pressed, aso I was with "no possible play yield all".

To search the problem and read the card I missed time, I won that game but miss the match.

I was playing a game where my opponent had a Narset, Parter of Veils in play and I had Sylvan Library.
I used my draw step to dredge Life from the Loam from my graveyard, the Sylvan Library triggered and it didn't let me draw a card.
It should be a bug, because I didn't draw any cards that turn.

Bugged Card interaction or lag w/ casting a spell causing my timer to expire and not permit me to make the intended play almost resulting in a game loss.

Chancellor of the Annex triggered only for the first opponent in a 4 player game of commander, and did not apply the mana tithe effect to the other two opponents

I had a Bolas' Citadel in play and a Toxic Deluge on top of my library. When I tried to cast Toxic Deluge, I lost 3 life, but didn't get any additional prompt to pay life, and Toxic Deluge remained on top of my library. I lost 3 life every time I clicked on it, but was able to undo back up to my original life total after going all the way down to 2 life. Ultimately, I was never able to cast my spell, and had to pass the turn, and my opponent killed me.