Hi gracebarto
to All Things Plants!
I live in Florida where Ixora are commonly grown as hedge/landscape plants. I have a couple of
Flame of the Woods (Ixora) in the ground as a small hedge and one
Flame of the Woods (Ixora coccinea 'Maui Red') that I keep in a container trained as a tree form. Ixora like high humidity so you might try misting the leaves daily to see if that helps. You can also sit the containers on trays of pebbles, making sure to always keep a bit of water in the trays which will raise the humidity levels around the plant.
Hopefully others who grow Ixora will pop in with some tips too!