I have checked in the HDRI backdrop, the skylight default lower hemisphere is unchecked
And the correct reflection only show up when i check the actor hidden in game box, of course it is not a desire result.
Is it a bug or any setting ii should check, because in UE5.3, it works very well by default.
Whats your reflection method? Are Screen Traces on? Hardware Raytracing with Hit Lighting?
Hi,
I’m having a similar issue with the HDRBackdrop in 5.5.1. I do have Lumen and Hit lighting for reflections enabled, as well as Screen Traces option on.
It’s been quite inconsistent within the same projects - it usually works in the beginning, but it stops working randomly later on. I can’t say that I’m doing something specific that makes it break, but it does.
Once thing I’ve done today is to change the mesh type from Dome to EnviroBox soft - the reflections came back when I did this, but then they went away when I re-opened the same project.
If anyone has any insight into this, it would be appreciated, as the randomness of it makes it hard to figure out what’s going on.
Hi,
You would need to turn the Real Time Capture box on the Skylight of the HDRi backdrop BP to False; this will instruct the editor to use the lighting coming from the HDRi cubemap image. The Skylight’s Source Type should be set to Specified Cubemap and the Cubemap section should be populated (see image).
Other lighting actors will keep working as usual but the skylight will no longer update automatically if you move large objects, delete walls, etc.
Alternatively, you would need to add a static mesh (floor) underneath it, add an Exponential Height Fog to the level and adjust the size of the cubemap. Make sure that the Lower Hemisphere Is Solid Color is set to False in the Skylight component.
Posting this as it may help someone out there 
[UE5.6]
