10 Round Ultimatium Not Giving Last Two Ascendancy Points

Finally Copleted the 10 round trial in the temple of chaos for my last two ascendancy points only to find that the altar at the end could not be interacted with to acquire said points.

The ultimatum was 10 rounds and stated i would receive ascendancy points if completed

The third boss dropped a fragment that you must place on a door near the purple portal. You need to do this until you collect the 3 fragments, then the door will open, and you will face the final boss. Only then will you earn the last 2 points.

You need to complete the 10 rounds of the ultimatum at least 3 times, but it can drop duplicate fragments so you need to do this more times, or you can buy the fragments with Alva and open the door. The final boss is a pinnacle boss; if you had trouble completing the 10 rounds, you will likely find it difficult to defeat him on your first attempt.