Blending and Effects Not Working As Expected in Instant Apps

[ArielLow2146]

I added a feature layer to a map with Destination Atop blending and a Bloom effect. In the new map viewer it results in a fade to white effect.

When added to a Basic Instant App it results to a fade to grey effect (so the blending and effect are still working but the map background has changed).

When I add it to the Media Map Instant App the Bloom effect stops working at all and I have a grey background.

In both apps I am using Light mode with no preset theme. I was able to get around this by enabling background color in the new map viewer but it would be great if that extra step wasn't necessary and the Bloom effect worked in the Media Map.

Please let me know if I'm missing anything or have gotten anything wrong.