Hi RolandP Thank you for your reply. I do not need to arrive on time; I would be very grateful if I can arrive on the same day.
I have tried to purchase the same route again. I can find it, but it shows that it cannot be booked. I have not received any email notifications about rebooking or refunds, so I feel a bit confused.
I have heard that there might be a replacement bus (EV), but I am not sure whether it will actually be available at that time, so I feel quite uncertain.
Also, the itinerary for that day shows that there is indeed a bus departing from Domodossola at 20:03, with a transfer in Arona to a train to Milano Centrale. However, my itinerary shows that I will only arrive at 20:12, so I definitely cannot catch that bus.