Inventory and Crafting Table Are Acting As If I Am Using A Controller (Cannot drag items between multiple slots)

When selecting items in the crafting table and inventory, instead of the item being "picked up", the slot you are trying to select gains a white border, as if you were using a controller. You are also not able to drag items throughout the inventory, making "PC Crafting" practically impossible. This bug, however, does not seem to affect you at all if you're in the chest GUI. I have left two screenshots below of an item being selected in the inventory and in a chest.

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^{Mod note by [Mojang] Mega_Spud (Jay Wells) - Simplified this ticket to the most prominent of the multiple bugs posted here.}