The “Mother’s Lament” gem is not activated by some abilities across classes. For example “Rain of vengeance” (demon hunter) or “Consecration” (crusader). Also, the gem is not activated by poison damage, although the activation condition is inflicting any damage.
There is another problem that another user already wrote about, namely, the time of the increased critical strike chance and atack speed with the help of the Vithu set is not extended.
Device Type: Smart Phone
Device Model: Poco X4 GT
Device Operating System: Android
Diablo Immortal App Version: Current Version (2.1.3…)