Unwanted Camera Vignette only in HTML5

Started a fresh Unreal project with 4.21.2 as a C++ base. Created a new level, new game mode, character, and character controller, and created a blank white sprite background and a grid out of a gray box for a ‘tilemap’. I set the “Viewport Texture Tint” to be white on all imported sprites.

Every sprite ends up washed out with gray after I build lights. Changing the scene to unlit makes everything appear properly white, but in the editor and in the builds they appear gray-er. Worse, HTML5 has a vignette ring that’s centered on (and moves with) the camera. Brightening/intensifying the Env Lights causes sprites to be washed out with white instead of gray.

I thought sprite surfaces were not supposed to react to lighting? No light objects interact with them but everything is not displaying at the color I’ve created them at. HTML5 appears to completely incorrectly handle the sprite textures, forcing me to use environmental lighting;

You can probably recreate this by putting any white sprite into an empty C++ project and try to export it to HTML5.

edit: I’ve resolved the ‘washed out’ in-engine look, it was the tone mapper. However, the HTML5 view is still showing that ‘spotlight’ effect, when the entire game should be “illuminated” neutrally as any other sprite game.

Here’s another example of what’s going on in HTML5.

I don’t think it’s connected to the ambient light levels. However, I’m not sure what the cause is. Is it a property of the camera itself? sprite texture? The material? Why does it show more starkly in HTML5 and more washed out in the game engine?

It looks like it’s shading or shadowing, but if so, why is it affecting sprites and tilemaps?

Never mind on the primary/engine view. The washed out effect was definitely the Tone Mapper, which I’ve subsequently disabled via console on the game’s start.

However I’m still getting this effect in the HTML5 version of the game. So it is definitely a separate problem… or at least the console command will not work in the HTML5 mode.

Now that I’ve reduced the problems to just the HTML5 build, I’m re-creating this thread in the HTML5 board. However I’ll keep an eye for both, I absolutely need a solution!