Where are you located? I wonder if these had some cool/cold damage during shipping, or more likely the brown/yellow is a result of them being removed from tissue culture (high humidity, "perfect" conditions) and not acclimated slowly enough to real world conditions. They seem hefty enough, but there are a few things I would change. Hard to tell from the photo but to me your mix looks a little "heavy".....too many fine particles. I would loosen the soil up by adding a bunch of perlite and also some fine bark pieces (you can buy orchid mix and mix it in or even some regular small pine mulch pieces). This gives a soil mixture that holds moist but contains a lot of air too. Remember these guys are naturally growing in the tropics, along and on trees where mix is very loose and airy. Second, at least initially I would put each pot in a large clear ziplock bag......leave the top open but it will still raise the humidity around the plant a bit. Once they root in well and get growing you can remove this bag. I routinely do this with new cuttings too. Good luck, they are one of my favorite houseplants. Note that it is normal for very white areas of the leaves to brown easily, especially when conditions are not the best (like inside in winter)./

Hi woodnative, I’m in the uk and it was around 0-5C the week they were sent, I had wondered if it was damage from the cold.

I was considering adding perlite to the soil this weekend, it’s gone weirdly compacted (never had a soil do this before!) I’ve loosened it up with a skewer.

Thank you for your advice, the propagator comes tomorrow so I’ll see how they get on in that, And I’ll add some perlite to the soil too

Certainly get them in a looser soil they will make better roots. Not sure exactly what the propagator you mention looks like.....I assume it is a plastic dome on top and a heat mat underneath. A little extra bottom heat is always good for rooting, esp. in winter.......don't make it too hot either. If the propagator has a dome that covers the plant completely I would leave it open a little to encourage some air exchange. Make sure the soil stays slightly moist but should never be soggy. The extra perlite should help a lot. Like I mentioned I like to add perlite and also some "orchid mix" (made up of a lot of bark chunks etc.) to the soil. Good luck with them!