The game has been plagued by a weird bug for a while now (since 2016 in fact: rP18443) - tree leaves show up as extremely bright in reflections.
The reason for this is that they are overwriting the alpha for nice smooth transition from leaf to ground, which works well when over-ground, but makes them show the skybox (which is rather bright) in reflections.
Because trees are usually in the shade, this is particularly jarring. See screenshots:
To fix this, the simplest solution is to reduce the blending effect so that leaves are mostly opaque.
Related to #5125, which it makes, I think, somewhat irrelevant