Two Different Teferis & Two Different Bugs in the Same Match!
I experienced two bugs, with two different Teferis in the same match!
First bug,
Opponent has M21 Teferi in play, 2 Glass Caskets exiling some perms, and lands. I have a Gideon Blackblade and some lands in play. Previous turn Teferi phased out Gideon. Now he's back with a vengeance on my next turn ready to send Teferi to exile...except I am unable to activate his planeswalker ability. The game immediately asks if I want to move to combat, recognizing that I had a cold draw.
I should have been able to use an ability after Gideon phased back in.
Lose that game, let's go to Game 2 for the 2nd bug with a different Teferi.
I cast Agonizing Remorse, seeing M21 Teferi, WAR Teferi, Dream Trawler and some other cards. I take M21 Teferi because it turns out he's hiding a pithing needle in his phase pocket naming Gideon Blackblade (of which I'm running quads).
I'm trying to win this game, so of course I top deck another Agonizing Remorse. I cast it and what should to my wondering eyes should appear? Two WAR Teferis! So, I take the win-con (Dream Trawler) hoping these Teferis will play nice.
Arena was nice enough to let me know the cards in his hand after the first Agonizing Remorse, but I suspect it had enough of my agony, because after the second Agonizing Remorse every extra card he drew showed up as another WAR Teferi. I could hover my mouse over any card in his hand and it would show the full picture of WAR Teferi.
Later that game I would play a 3rd Agonizing Remorse, and now Arena was having remorse for how it treated me. Revealed just one Teferi, (I took the other card) and all subsequent draws showed the opponent's sleeve as intended.
First attachment is the first bug.
Second attachment is the 2nd bug.
Third pic attachment is a screenshot of the 2 Teferi's in hand glitch.