I noticed that at rates below one, for example 0.5. If you pick up corn, for example, instead of 3 you should collect 1 or 2. It gives 0. And zero value falls into the inventory. GatherControl + ZLevelsRemastered.
I don't know, maybe there is a plugin conflict. Or the problem is in the second plugin.

Have you tried gathering without ZLevels Remastered? If it still happens, try without Gather Control but with ZLevels Remastered and such.