Dendrobium Aggregatum not blooming in 3 years

[lusenok]

Hello friends. I have a large dendrobium aggregatum what never bloomed for me and, frankly, I'm losing patience. Please tell me what could be wrong here.
It's a big fat plant with 30 or so pseudobulbs residing in 8 inch shallow pot with coconut coir / bark mix. It diligently grows 2 or 4 pseudobulbs every year but doesn't bloom. Last winter it got winter rest December to March. This year it hasn't had a drop of water since November 1st.
Light levels in my house are kinda-ok. I have a southern window and managed to bloom a few cattleyas, dendrobium phalaenopsis and even Neofinetia.
Sorry for the poor picture quality, we have a very dreary weather today in the Northeast