Getting transparency to work on image media Sources

Hi! I’m new to unreal and I’m trying to use image media sources as 2D cards in a map I’m creating. I’m having trouble getting the opacity to work as I want. I have a png sequence with alpha imported (I’ve also tried exr and tiff) into the img media source and I’ve got the blend mode set to masked so that it will still cast reflections and shadows, but the image’s alpha does not read at all on this mode. It shows up normally when the blend mode is set to translucent, but then I don’t have the ability to get the shadows and reflections I’m looking for. Any ideas why this is happening? I’ve looked up many tutorials online and they all say to set blend mode to masked, and it seems to work for them.