Monster Meat and Rot won't stack anymore on cursor picking?

[MondayNight]

I've noticed for some time now an issue with, as per title of topic, Monster Meat and Rot: when player has backpack and full inventory (character and backpack), picks with cursor said MM or Rot from ground and repeatedly drops-and-picks it to trigger stacking of MM/Rot from 1-screen-away on cursor stack, old stacking isn't happening anymore. Tested it on both personal and public servers, vanilla variants. Anyone else noticed this behavior? Was very useful when cleaning world of Rot for example, or picking MM from dangerous/hard-accessible places (Tentacle Traps, from water, etc). I believe this inability to stack MM/Rot occurred when Webber update came out.