After updating to newest fabric API blocks don't drop (I tried mining terracotta slab). As I have the same problem with blocks from at least two other mods (Epicurean and Cotton Resources), I thought I give the info to the coders.

[1.14.1] Fabric API 0.3.0-pre build 157a works just fine, but not later version

FabricMC/fabric#210 here are more people who actually know programming (unlike me) talking about it.

EDIT: Fabric API programmers found where the problem stems from, so it is not an issue with this mod.

I think this might be an issue with the API itself rather than with Extra Pieces, Epicurean Gastronomy or Cotton Resources. Is it still happening with the latest API version?

Yes It has been hapenning in .165, 166, .167. And I checked other mod (Blockus), works the same. I'm gonna write API author.