Hati Yours is a DCT diesel isn't it. Does yours labour?
Yes it does in Eco and normal mode. Sport mode keeps it a bit above where I would keep it if it was manual, but the other two modes get to 6th around 60 km/h or thereabouts so your revs are only at around 1200. This is all in the name a fuel saving. My theory is that Hyundai wouldn't let the engine management allow such low revs if it was hurting the engine.
I don't like it either so I drive it in Sports when it bothers me. In that mode drops a couple of gears and gets close to 2k in revs. Haven't driven it enough yet (just ticked over 8000 k in nearly a year) to work out how to keep it where I like the revs to be. It does have tiptronic so can be driven like that but didn't experiment with it much as yet. At higher speeds it keeps the revs closer to 2k (just under at 110) so it's usually low speed town driving that feels like labouring.