[Alexandra Sideris won't give me missions]

It may be one of the Midnighter Arcs causing the lack of introduction - my Rogue Water/Bio Sentinel completed said arc villside and did -not- get introduced to Alexandra Sideris.

However, my Elec/Elec Vigilante Brute -did- complete the arc both heroside -and- villside, and was introduced to Sideris.  Perhaps the villside arc from Ashley McKnight is the cause?  Will test on my Savage/Bio Hero Brute to see if he's introduced, as he's only done the heroside version.

EDIT: Savage/Bio Hero Brute that only completed Montague Castanella's Midnighter Arcs -did- get introduced to Sideris, as well.

[Alexandra Sideris won't give me missions]

Also having the same issue, and got the same dialogue as Cinnder and Emerald Fusion did.  Redside on Duke of Vaungur, Water/Bio Sentinel, a Rogue.