Any flight cancelation.
They cant do it on phone, I always put in the flight and either have the PAX go a bit early and gets its ticketed at their ticketing desk, or contact their airport office on phone- but sometimes hard to get thru to them
All of which is pretty ridiculous.
I've had PS rebook passengers on LY on the phone (like all other airlines do). I've also had that they would hold up the KBP - TLV flight when the flight from JFK was delayed if a significant percentage of the flight was continuing to TLV. SU refused to hold a flight for a few minutes and left many passengers stranded in Moscow Purim night. On top of that they denied ANY compensation, blatantly lying about bad weather in Moscow. (They were delayed 1.5 hours in NY, and according to Accuweather history, there was 0.2in of snow on that date in Moscow (and no snow before or after either).
But again, none of these are amazing....