I have an ORD-ZRH-BOM round-trip ticket on United and Swiss. On the outbound segment, I was rerouted via FRA (partly on LH) because of cancellations. As a result (I think), I was unable to make online changes to the return segment. I had to call UA and get the return flight changed (without additional charge). I thought that after this change by phone I will be able to make further changes online. Now it does present me with the option to change (no longer says "call us"), but for any date I select, no flight is found for BOM-ORD. It says "We couldn't find an exact match. There are no flights for the selected date" when of course there are. Does it mean online change is still not possible?