Empty Call Directory Extension exceeding memory limit

Hello, I am trying to add a Call Directory extension to my application, but the extension runs out of memory immediately when launched. I have an empty CallDirectoryHandler class generated by Xcode, which looks like this:

import Foundation
import CallKit

class CallDirectoryHandler: CXCallDirectoryProvider {

    override func beginRequest(with context: CXCallDirectoryExtensionContext) {
        context.delegate = self
        context.completeRequest()
    }

}

extension CallDirectoryHandler: CXCallDirectoryExtensionContextDelegate {

    func requestFailed(for extensionContext: CXCallDirectoryExtensionContext, withError error: Error) {
        
    }

}

My breakpoint inside of beginRequest never hits, and the stacktrace doesn't give me any clues.

I have a small example project that loads 1 million fake phone numbers into CallKit which only uses 2MB of memory in the app extension.

I'm not sure what else I can do to limit the memory usage in my extension, does anyone have any idea what is going on?