In Plain Sight NOT WORKING

Is anyone else having this issue? Doing the challenge perfectly, not being spotted and killing both targets well within 10 seconds of eachother after setting off the fireworks display.

I have seen a couple forums mentioning different possibilities as to why its not working but I can’t seem to find a solution

Hope you guys can help me!

Wait for Dalia to lean on the balcony and Victor to stand still. Shoot Dalia first. Make sure you’re not getting spotted by anyone while escaping.