I don't think EF has ever tracked the pricing of award tickets. All that EF can do (and AFAIK has ever done) is to tell you when there is inventory available in the relevant booking class(es). So there is no difference there.

This is in contrast to cash fares, which are published to the GDS by airlines. EF will list those. But even then, airlines sometimes have private cash fares that they will sell on their own websites but do not formally publish. EF likewise can't track these.

I suspect that the problem you are facing may be to do with the position (AIUI) that DL has no fixed mileage prices for award tickets any more, but changes these at its discretion. EF can tell you whether there's availability, but not what DL will ask for an available seat - and that has always been the case.