My variegated hoya hearts keep dying

[eggshell]

I ordered about 20 hoya kerris on etsy, about 8 of them have died.
They arrived in plastic pots. I red that terra cotta pots would be better for them.. so I transferred them into unglazed cotta pots!
Soil is staying dry. They are getting indirect bright light. It start with a brown spot and ends up looking super scary . Please help.

I have been doing some reading online and I am considering going soilless. I think it might be something in the soil that they came in.?
Im thinking coco coir, pumice, worm castings, lava rocks, aquarium gravel and activated charcoal? *sterilize everything?!

 

[Marck]

Hello again, of course, we spoke previously in your other thread about the rot on your Hoya kerrii leaves and the unlikeliness of the rooted leaves ever developing into vines since they are without stem tissue. Still, the rooted leaves can live indefinitely in that state, though they often do eventually succumb.

I am sorry to hear that your rooted leaves are dying. At what temperature are you keeping the plants? They are sensitive to cold and will do best in a heated greenhouse or warm window in Winter. Improving the drainage by replacing the soil might also help, but of course, there are no guarantees.