Mirroring a hollow element results in a solid mirroed element

[Cad2homebuild]

Hello skilled designers. I wonder if you would understand why this hollowed part works fine, but when I mirror it, the second instance is solid. I'm looking to create a 1/4 section & then radially pattern it. I'm including the solidworks file below.
Thank you in advance for your advice.

 

[Cadasio]

Hard to tell without seeing the actual part file, but are you mirroring the whole body or just some features?

when you do the mirror command, expand bodies to mirror and then click your component(s)

 

[Cad2homebuild]

Thank you. I tried both methods. I first attempted to mirror the whole body, and then just features. Neither worked, but after some rebuilds, I was able to get the part to mirror as a hollow segment today.