The Spiteful difficulty level isnt difficult at all

I upgraded to the Spiteful difficulty level, and its not at all as hard as it should be. A few times the computer has failed to make a move to block me. For example, I had a queen turned up on the top of my pile of cards, and the computer played a bunch of cards ending in a jack, then stopped even though it had a queen that it could have played onto the jack to block me from playing my queen.

I understand that at the easier difficulty levels the game is programmed with these kind of "errors" so that players have a chance, but I expected that the Spiteful difficulty level would be as difficult as possible. The computer shouldnt be making these kind of "errors." I wrote to the dev about this two weeks ago, even followed up with some screenshots showing the problem, and never received a response. In the menatime, I am winning most games at the Spiteful difficulty level, more than I used to win at the Hard level. So I wasted $5.49 on a difficulty level thats not difficult at all.

Drdul about Spite & Malice, v2.11.1