Realtime reflection probes are not supposed to work by default in Standalone Builds. Their baking has to be called from the Scripting API.

The editor does not correctly mimic this behaviour as it bakes the probes on every frame in the Game View.

How to reproduce:

1. Open a new project
2. Create a Reflection Probe
3. Create a Cube next to it
4. Create a sphere next to the Reflection Probe
5. Attach a 100% Metallic and 100% Smooth material to the Sphere.
- Note how, if the Reflection Probe Type is set to Realtime, it is re-rendered every frame if any of the objects is moved.
4. Build scene to Standalone and run it
- Notice how the Sphere is not rendered the same way as in the Editor

A workaround would be to either call reflection probe rendering from a script at the same interval as the Editor does, or use Baked reflection probes.