Layer bug in Unity 2018.3.10f1

In this version of Unity, UI objects such as images are counted towards the UI layer by scene cameras even if you switch their layer to something else.

I have an extra camera that is meant to render only objects in my custom layer but it doesn't work. If I set it to render only objects in the UI layer, the specific object appears.. But this of course is not what I want because then all of the UI objects are shown and I only want that 1 specific object to be rendered to that camera.

I'm working on another project in the LTS Unity version and this problem doesn't exist there. Wanted to mention it so it can be fixed in the next versions