Nilfur's Precision gem not dropping after defeating Ancient Nightmare (Zone event) on Hell I, Hell II, or Hell III

Bug Report
1

In addition to a description of the bug you are reporting, please provide:

Device Type: Android
Device Model: Infinix ZERO 30 5g (Model: Infinix X6731)
Device Operating System: Android 13,XOS 13
Diablo Immortal App Version: 2.3.4