A few possible causes:
- Reflection capture brightness is too high in conjunction with the dynamic lighting of those meshes (since they’re movable)
- The meshes’ materials have an incorrect setting / node problem / texture settings issue
- Skybox is not set to Unlit, or the HDRI is too bright / not set correctly for the scene
With the HDRI, it comes with a dynamic skylight (not stationary), so if a stationary skylight was added after or before the HDRI was, then the lighting for movable meshes could be getting multiplied. It’s suggested in the doc page for HDRI to not add a second skylight, though I think it depends on the scene and the settings. Thus, I would check to see what happens to the meshes’ lighting when deleting or simply changing the stationary skylight to not visible. If changing it to not visible (by unchecking Visible), then it still calculates and applies Lightmass indirect lighting for the skylight, while direct lighting wouldn’t be there. It’s the direct lighting that’d seem to be contributing to the brightness if that’s the case.
Indirect intensity can also be scaled in materials details panel, as well as in the lights of the level. Perhaps lowering it would offset the brightening and render at the intended shading.
Certain settings in the textures of a material/mesh can also generate incorrect values or effects. Too high of compression, or perhaps no compression combined with a high texture resolution for movable meshes could conceivably do it. Parameters such as Brightness, RGB Curve, Brightness Curve, and Saturation are possible, but not as likely I think…though adjusting one or two could adapt it to the lighting better. If using HDR textures, sRGB is supposedly required to be unchecked, and this is a problem that’s best to research further if other attempts at fixing don’t work. I simply suspect it because I’ve read a number of posts / articles concerning how HDR is not always conducive to a particular color mode / depth in getting the optimal result (eg, there’s almost half a dozen ‘standards’ in use for different scenarios).