With number "Airdrops amount(spawn after crash)" set to 0 there appears to be an issue.
When one of the locked crates spawns with a supply signal inside of it, take the supply signal out and it does not allow it to be called in.
Drop it on the ground and pick it up it shows X Supply signal 0
If you spawn a normal supply signal in or loot a supply signal from any other event/crates. drop that on the ground and pick that up it shows + Supply signal 1
It is almost as if the "Airdrops amount(spawn after crash)": 0, define makes any supply signal within the locked crates spawn as if it is not a supply signal