Creative mode blocks and objects bug

What I expected to happen was is that you don't need to hold down the left mouse button to take or move blocks or objects from the inventory( the one where you can choose any block or objects). Instead the block moves back to where I got it from when I try and swap a block or object it would go back to the inventory like the one I said before. the only way from me to move and get new blocks is that I have to drop them and make an empty slot for them.

what i thought that should happen is that i only need to click on the block or object so i can move it but it doesn't. click on the block or object to swap it and it doesn't.

What actually happened was i try and choose and block or object and try and swap it and it doesn't and the only way that it works is if there is a empty slot and i have to drop a block to make it work

Steps to Reproduce
1. be on creative mode.
2. fill your bar with anything
3. try and swap it for another object( this is where it doesn't work).
4. press q to drop an item so there is an empty slot
5. fill that slot with something and then it should work