I have not seen / reported this issue since November (
https://forums.playcontestofchampions.com/en/discussion/108435/cheated-by-aq-map2-again-today#latest) but it has happened twice to my Alliance this week. On Sunday, when fighting the final boss (Kingpin), I fought him, bought down his health a fair bit, then got knocked out. My Alliance mate then fought him, but he was BACK TO FULL HEALTH. So, all the progress I earned was not saved upon fight end / exit, but the pain was (my Champ was still knocked out).
Then, just this morning, it happened again!! This time it happened to mini-boss #2 (Scarlet Witch). One Alliance member attacked, made huge progress, got knocked out. Next member attacked, mini-boss back to full health

I only have 2 members in my Alliance at this time and we are both "medium" strong teams (4* and a few lower rank 5* Champs) .... making it through AQ MAP2 is a real challenge for us. it’s fun and rewarding because it’s a challenge but it is right at our upper limit of what we can do (often need to use a few revives and heals to take out Kingpin). Because of the way we have been cheated by the map today, I doubt we will be able to finish off the map.... super disappointing. Especially on the final day of the AQ.