OH!! that is why they looked so overtired on my 2 SIN-ZRH flights.
I didn't know that.
AF let their crew 2 nights in SIN and SQ let them rest 2 nights in ZRH and CDG too.

I was so happy when LX opened a direct flight to SIN but had bad experiences on the 2 SIN-ZRH flights I had recently. Flight Attendents who are usually very professionnal and smiling on LX were very distant and did the service like robots in C. No smiles, no eye contact, no small talk... They looked like they just wanted to go to sleep. I wondered why as on the 2 ZRH-SIN segments the crew were very good as usual.

I am thinking to switch again to SQ on the westbound flights. LX should be careful with this matter. I don't want to endure apathetic crew on all my flights back to Europe.