Normally when you hover over an item in inventory and press a hotbar shortcut, the hovered item goes to the respective hotbar slot. I have programmed first slot of my hotbar to a side button of my mouse. But when I open any container to quickly take an item using the side mouse button, it doesn't react at all. Also I noticed another bug/conflict: selecting the first hotbar slot while standing calm is working fine, but you can't select it while sneaking/pressing Shift.

The bug appears in Survival and Creative modes.

My mouse: Defender Datum MM-070