Disconnected after Dominus fight on Normal

I know this is not new (and that talking to Dialla gives a wp to Cruel, a nice feature that works), but whenever I talk to Dialla after a Dominus fight on Normal (and only here) I get disconnected.

I've tested this, as I'm currently leveling chars for the Reach level 65 challenge. It happens every time.

It was more annoying than an actual problem (because I would just reconnect and have my next wp available), until I started getting blue screens, which is really unpleasant.