My gas bill from Louisville G&E shows a gas component cost on each bill. Interestingly, when gas had dropped by 2/3 that item went down 10% (for our Democrats out there 10% is a lot less than 2/3!).
It wasn’t until winter heating season was over that the “gas component cost” went down any more (and not nearly 2/3). Which was roughly 9 months after NG made the 2/3 drop.
I called LG&E to get an explanation of “gas component cost” really means. Pi**ing into the wind on that.
I bet the discrepancy you sense is the result of them buying in advance, on contract. While the "spot" market drops, they may be on the hook to pay the higher price they promised. The reverse also happens - spot prices rocket, and their contract price doesn't (not immediately at any rate).