After firing her black, 3 special tiles were created, each of which is supposed to “eat” enemy damage. These used to last 3 turns. Now, after creating the tiles and making my move, the AI moved, and each separate match that happened in the resulting cascade reomoved one of her tiles. Meaning that all her tiles were destroyed in one turn by the enemy. I don’t think this is how it used to work, and I think it’s definitely an error!
That is how it’s always worked. Each tile blocks one attack, and each match counts separately – just like they count separately for adding strike tile damage, or when calculating whether powers that block damage above a certain figure will kick in.
It sounds like you might be combining Elektra’s black with Spider-Woman’s. Spider-Woman’s lasts for longer, and has a countdown for duration instead of blocking one hit per trap, but Elektra’s does damage with each hit it absorbs. There’s a trade-off there.