When it is not growing it has a good chance to be rotting. It does not need any water, it will just rot the cutting. The mix has to be really fast draining, I have found the gritty mix as found on the container growing forum to be the best mix for growing Plumeria without rotting during the dormant period, or when starting a cutting. Al

My Plumeria rooted within 2 weeks. I was astonished at how fast it had a deep hold in the soil. If it hasn't rooted by now in damp soil, then I would remove the cutting and allow it to dry before planting it again. It only needs a little bit of water. Make sure to use rooting hormone to be on the safe side. The only thing that I can think of that I really did different was putting a light really close to the growth points at the top. The leaves start out as these small green bumps at the top of the stem, and within a few days they were already starting to grow. If it is not too late, I would try that. But be warned, rooting is the easy part. The leaves are very sensitive to temperature drops. One day in the low 50s with my windows open made it loose all its leaves. Hope this helps because these are really cool plants if you can get them to take.

I have been moving my Plumeria into the house every night for the last two weeks, and back out into the sun every day about noon when the temperature gets up over 60 degrees. It has flower buds on it and I am hoping it will flower inside in my relatively low light. It is so big and heavy its all I can do to carry it, so it stays inside from now on no matter how warm it gets outside. Now I am thinking of how I can rig a light for it. Al

Thanks for your answers.
I've read on another topic to use a pin to check if it's rotting and there is white juice came.
I watered it before just because I tried and soil mixture was dry and as I understood it supposed to be damp. The mix is fast draining indeed.
I'm just afraid of pulling it out of the pot in case that it actually started rooting and I'll break the roots. Or are there signs on the outside right away when its rooted?
May be putting it in a some kind of greenhouse will help?

At the time the picture was taken it looks OK. If you now have it in a warmer place it will probably be good. I would not water again until you see some growth. There is ample water in the cutting until growth starts. When there are no roots to use the water, vapor is good enough to start root growth. More warmth is good. Al

You should water once until you see leaves growing. heat is a factor as well. i root mine in a black nursery pot add 2 inches of rocks. this will promote heat that encourages rooting. check fir root rot. i think you watered it too much