Switching and healing

I played some psychic deck earlier, I forget what it was called, but every time I hit it, on my opponents turn, it kept fully healing... It had no ability to heal and my opponent didn't use any cards to heal either... But I thought, maybe a bug, and restarted the app.

I just played Iron Valiant EX deck, it has an ability that puts 2 damage counters when switched from bench to the active... But every time it was in the active spot, my opponent just switched it out, no item or stadium or abilities, I took a screenshot but I can't upload here, of the battle, I couldn't see how he did it, I was kind of hoping someone could see it... So they were basically placing 40 damage counters on me every turn and I couldn't figure out how lol...

I the bench they had a Xatu that has a draw 2 cards if you move a psychic energy to your bench from your hand, ability, or something... 2 Mimikyu with the prevent damage from V and EX cards... And a Pidgey... So no abilities to switch out... The last Item / Supporter they used was a Arven... No stadium that reduces retreat cost, it was Lake Acuity... No energy removed to retreat either and the 1 Iron Valiant EX had 1 energy attached when it requires 2, to retreat... I don't get it lol, glitch maybe? Bug? Desync?