Version: (make sure you are on the latest version before reporting):

latest 1.16.1

Issue description:

if you have a player transmitter active, while crafting or picking up a reactor, parts of it start charging in your inventory. This means it's no longer placeable, until its fully charged (30M!). You get "you need X more parts", but they're present, just not in the same stack as the stack I'm trying to place now (due to not stacking because they have different levels of charge).

Steps to reproduce:

Place an active player transmitter. Craft the reactor in stages. You'll not be able to place it, because the parts have different charge levels. (similar applies when trying to harvest a reactor too)

Oh, thank you for reporting!! I will fix it in the next update.