I was going through my accounts and happened to spot a newly discounted game at the top of the latest deals on another aggregate website with GG.deals set to the equivalent filters but did not have it listed after a refresh. Turns out GG.deals did have it listed but only if I went in to the actual game itself.
From the Deals page, minimal filters:
From the Game page, minimal filters:
Deals page listed vs sidebar:
I'm guessing it is because the Deals page is not using the same list of Stores that are implemented on the backend which is why GamerThor shows up for the individual items but not the Deals search itself:
Turning off the filters (leaving just name "sable") still had gamebillet as the best deal. As far as I know there is no way of knowing GamerThor (or others if there are more) have sales because it cannot be added to any filter or Alert. Maybe GamerThor is a newer integration, not quite completely rolled out and this is the only one like this but just figured I'd give a heads up in case it isn't and see if other people have seen the same discrepancy.