Found some diamonds, 8 diamond ore. Got to the point where I finally was able to get a Diamond Fortune III Pick, but out of those 8 diamond ore I only got 12 diamonds. If I recall correct in the past I got tripple the amount of diamonds from 8 Dia Ore.
8*3=24
this time I only got 12.
Also I noticed that mining redstone ore with a Fortune III pick in this version gives only the same amount of redstone as mining it with a regular pick.
Same happened with coal. I sometimes only got the lowest number possible out of a full 10+ block coal veine.

If you could check into the coding if there got a value changed or it might also have something to do with the new chuck loading which causes blocks to not render properly and that might also causes it. But I had tried mining coal with that feature enabled and disabled but it resulted always in the same. : No change between regular pick and Fortune 3. Only sometimes I'd get the Fortune 1 or 2 effect it seems.