Heres my take on this having played around with media textures a lot (since it seems the web view is displayed via media textures).
Media players do not work on android either - and this is because the media texture requires the new style and color mode on windows/vulkan… etc, but on android, it still works only with the old style + external.
My assumption is that the media textures for web view use the new style, and hence do not work on android for this very reason. This might just be a very simple C++ switch since non of this is exposed to BP.
Some help would be appreciated.