Dendroibium trigonopus not growing

[Anyuta]

Hello,

I am new to dendrobiums, I have only 2 of them and both are giving me troubles, or rather I am giving them. Could you please help me figure out what is happening to my dendrobiums as it seems like I am so bad at growing them

Here is one, trigonopus, and it's flowering right now. It had 3 flowers, now left only 1. I bought it blooming from orchid show. Now this baby appears to be totally dead, and if there wasn't a flower hanging on it, I would have concluded that it made its way to heaven. But the flower is still there and I hope that maybe it's just sleeping or something? I water it once in while, letting it to go quite dry between waterings, but I don't see any new bulbs developing at all. I see some roots down there, everything else seems hollow. How can it be dormant at this time of the year?