I am sure that they showed up in the early versions of P3D V5.
That's not possible, no P3D V5 versions ever supported DirectX 11, it was always DirectX 12 since the first release, and operator logos in P3D 4.4+ are made using DirectX 11, which is no longer supported.
With the current situation of crashes due to VRAM exhaustion and DX12, we decided not to use DirectX anymore in P3D V5 but, instead, use a new feature that has been added with 5.1, that is Render to Texture using HTML5, which should be hopefully more reliable.
However, this feature is not complete yet, because it still lacks a crucial feature we need, that is support for non-square textures ( all GSX liveries are not square ), so we need it to be added by LM first, in a future update.
The, after LM adds it, we can START working on it, to translate all parts in GSX that used to use DirectX to this new system.