1st time in top tier and dont understand how these work

As you can see in the video, i have the exact same custom preset as the default weapons preset made by the game, in my own one i cant use the Flares/Chaff (BOL) but in the premade one i can. What am i doing wrong?

Your custom bugged. You have to remove it and make it again.
They bug sometimes.

I had the same bug with a different jet. Try to unequip and equip back the loadout, I think that’s how I fixed it.