SwiftUI vector image is showing as purple square in testflight build

I use SwiftUI to display a .svg image. This is my code:

ZStack {
       VStack {
            HStack {
                Spacer()
                Image("logo_yf_head")
                    .resizable()
                    .aspectRatio(contentMode: .fit)
                    .frame(width: 70, height: 70)
                    .padding([.bottom, .horizontal], 16)
            }
            Spacer()
        }
        (...)

This is working in debug build and in a signed ad-hoc build.

But when uploaded and installed from testflight i have following problems on all devices:

the icon is shown as a purple square or is blurry. This changes at runtime. It even flickers sometimes.

My asset attributes look like this: