In the Inspector, the Setting button says Warehouse Kit. When I click on the Instrument slot, the window opens up with an image of a drum kit and the name Studio Brush Kit.
Strange. I have two Warehouse Kit channel strip settings.
One is in: Legacy > Logic > 04 Drums & Percussion > 01 Acoustic DrumKits.
The other: Legacy > Garageband > Drum Kits.
The first uses the EXS24 and the actual kit is the Warehouse Kit as expected. The second one uses a simplified EXS instrument (no editing possible) but the kit used is also the Warehouse Kit. Not sure how you're getting the Studio Brush Kit there!
When I use the right/left arrows in that window to try and change the setting, nothing happens. When I try the drop-down arrow in the name field, nothing happens.
Bizarre! Does this happen in a new empty project as well? I sounds like your content might not have installed properly? Weird.
So I close that window, since I'm supposed to access the Producer Kits in the Library, anyway, right? I open the Library and a list of Legacy drum kits come up. Since no Producer Kits are in this list, I search the Library for the East Bay Kit+, which is the one I want to use, and a bunch of different names come up, East Bay Kit+ among them. The names have dates next to them. I actually didn't pay close enough attention to the dates to see if they were significant in some way, but I click on East Bay Kit+ and a bunch of software instrument automation lanes for instruments I'm not using are added to my Main window, including ones that are named after all the elements of the Producer Kit (Leak, Snare Top, Snare Bottom, etc.) These tracks don't show up in a Stack and I don't see a way to flatten them. I don't know which one has the MIDI region and because the regions all have the identical name - *automation - I'm pretty sure I'm not seeing what I want to be seeing. When I double-click on them I don't see any MIDI events in the Piano editor.
The name East Bay Kit+ isn't on any of the Track headers.
The option to bounce a track (singular) in place is greyed out.
I imagine that reading what I've written here must be just as confusing as what I'm experiencing. Would you, or someone else out there, like to take a look at this project and see if you can figure out what is going on with it?
All of that sounds very strange...but sure, post some screen shots or upload your project so that we can see what's happening.