Yes, I know, in fact I knew since you said you got it updated already, when it was DX11 the SM5 was not possible, I had in my mind and asked nonetheless, sorry.
I tried hard to cause the, but Im afraid has something to do with the dev kit (Epic’s part). The materials you mentioned all of them are instances from M_OceanSSR. I have used the M_Inst_Ocean_SSR_Foam_Cubemap and it works in editor with SM4 selected, but when you package if fails and ask for SM5. So, the does not has anything regarding Shader Model. The usual behavior for anything which has high cost under certain scalability settings is to become invisible, which is not happening in your case.
As Im lacking a kit to have the same ability than you, the only thing I can tell you to experiment is an optimization on the plane and see how it will behave:
- open the BP_Ocean
- select each of the 3 meshes there
- in the details panel at right, look for the attribute called “Treat as Background for Occlusion” and make sure it is checked for each mesh.
- package and see if the still there.
If still doesnt work, but changed anything, let me know.