There is a bug in the Wave SDK for Unity with the material reflections from the skybox or from reflection probes.
In the editor, the reflections appear correct, when viewed in stereo with a headset.
The parallax of the reflections can be wrong depending on the axis the camera is facing : Reflections parallax is correct along +Z axis, but reversed along -Z axis and null along +/-X axis.
With a correct parallax effect, the content of the reflections will appears to be behind the reflective object. But with a reversed parallax effect, the reflection will appear to be in front of the object, which is completely wrong.
This was tested on a Vive Focus Plus and a Pico G2, with no difference. It was tested with the Wave SDK 3.1.6 and 3.1.4, with no difference. It was tested on Unity 2017.4 and Unity 2019.3 with no difference. On the Pico it was tested with the Pico VR SDK and it was correct, but it was incorrect with the wave SDK.
Having done these tests, I think the bug is caused by the Wave SDK.
I attached a unity project using Wave SDK 3.1.6 demonstrating reflections along each axis. When viewed with a headset, only the +Z reflections will look correct. If you test this unity project with an other VR SDK, They will look correct.
I also attached two screenshots of the project using two SDKs. The first screenshot uses the wave SDK and the second uses the Pico VR sdk. Compare the trees in the left of the mirrors in the right and the left eyes. The left eye sees more trees in the wave sdk screenshot, but in the pico vr screenshot, it is the left eye that sees more trees. The difference is very subtle in 2D, but very visible in stereo.
I hope this can be fixed.
Bug Reflections WAVE SDK.zip