Reflections on translucent objects are practically broken. The reflection map looks like a quilt

New to UE5, but this was a simple matter in UE4 so I don’t know what’s going wrong. I’m trying to use a simple glass texture, but the reflection map on it is ludicrously low. Great big triangles and squares instead of the expected high quality scene capture.

I have Sphere reflection captures, that’s where the image of the pool is coming from, but the image is super low res. The glass sphere here is the good example, I have the reflection on flat surfaces and it looks so bad it took me forever to figure out what was actually happening, since the triangles can stretch to the full height of a glass wall.

This seems like it should be something simple, but I even made a glass material from scratch to see if it was an issue with the imported material. Here it is, nothing fancy, and it looks fine in the preview window.

Any ideas?

This is just the quality of translucent reflections in lumen. There’s nothing you can do about it until 5.1

If this is true I am both relieved and bothered.

You can switch to a different reflection method such as deprecated raytraced reflections, but they don’t support lumen GI or skylight shadowing in reflections (plus multitudes of other features) so you’re just trading the patchiness for other quality problems, as people constantly post about here, so I would absolutely not advise it.