Name this orchid please!

[OrchidLyn]

Hello, New to this board, semi-newish to orchids (have had several over the years but not all types nor for more than a few years!)

I adopted this orchid (photos below) at a show last month. The seller's English wasn't great and it had no tag but she said it was an oncidium. I have a small oncidium, and it has very obvious pseudobulbs. This one has no visible pseudobulbs. I wanted to repot and taking a look at her roots, they also don't (in my newbie opinion!) seem like Oncidium.
I brought photos to my local orchid group and asked and everyone including the professional horticulturist speaker. Guesses varied but landed on: "Miltoniopsis."
That makes sense in viewing online, but I'm worried because without her blooming, I don't know the best way to take care (soil, light, water, pot, etc.).

I would love to know what she is so I can help her live long and prosper(!) at least to the best of my abilities!
Thank you!