Corrupted Nexus Tier15 quest fail twice back to back

Hi,

I've had two back to back tier 15+ corrupted nexus quest fails. Each time I killed the map boss and the map was set to completed.

The first time I died on the first attempt and after the 2nd attempt the boss was down but the area was not cleansed, leaving a corrupted field.

The 2nd corrupted nexus attempt 20 minutes later ended with the boss down, the notification that the ares is cleansed, yet the quest is still not completed.

The nexus boss didn't show up in both cases.

Thanks

Thank your for replying, meaning I should always treat a nexus attempt as a zero fail map and should always use a keystone with 0 revives to make sure I can retry, assuming that failing the map will make it possible to use a new keystone to try again rather than ending up in my two scenarios?