Ghost is being effected by Critical Resistance +90% in Act 6.4.3
In 6.4.3 Portal to D, the whole path has Critical Resistance +90%. Corvus' crits activate each time as they are guaranteed, but Ghost's crits do not. Both are guaranteed, so obviously there is a bug here. Crit Resist hasn't caused issues with guaranteed crits anywhere else as far as I'm aware.