Short flower spikes on rescue oncidium

[Maxx]

As this is my first post on the board, greetings to everybody from Hungary.

Although I am relatively new to orchids, in the past half year I have amassed a lot of rescue all-kind orchids from garden centers and hypermarkets.

Out of these refugees, an oncidium-type (?) orchid decided to bloom (I have no clue which one) from its new growth, but as you can see on the pictures the flower spike is very small, and one of the buds already blasted.

Pictures

Will the flower spike get bigger? An why is the orchid already blooming without the pseudobulb maturing first?

My growing conditions: western facing window, temp 75 F, humidity 60%, watering is weekly with 5 min soaking, fertilizing bi-weekly / monthly.

Thank you in advance for your valuable insights.