Flight cancellation

[MrsBeltane]

DS has a flight booked from London to Salzburg at the end of January. It's London to Dusseldorf, Dusseldorf to Salzburg.
He has had an email to say the London to Dusseldorf leg has been cancelled. I've looked at the airline website and they seem to only want to refund the first flight. Is that right or should he (me) get a refund for the whole journey.
I can't find the answer online.

Was it bought as a single ticket? Or did he buy them seperatly?

If bought together yes full refund. as the PP above says if he sourced them separately then no.

Thank you.
Bought together as a trip to Salzburg.

I'll phone tomorrow and brace myself for an argument.

Full refund promised by Eurowings.

Great news