I believe the card "Welcome To Sweettooth" from Wilds of Eldraine is bugging out in MTG Arena. I have a deck with this card in it, and I sometimes play it, but the card does not behave as it is supposed to because of some programming bug. So the card is an enchantment saga without the "Read Ahead" ability, so its Lore counter should be incremented by 1 one each of my turns, but sometimes the card comes into play at stage 2 or even stage 3 with ALL previous lore effects. There is no setup to this bug other than just playing the card, although I think the bug should be more obvious if you play this card at a latter turn during late game time. Actually, I think this bug may be due to there being ANOTHER instance of this card on the battlefield under my control, so maybe you should try playing 1 on turn A and then playing a second one on turn B. I have attached my log file as per the instructions in MTGA.