Pressing left-click and right-click at the completely same frame when holding a block will play the block breaking animation and sound, but the block still remains.
Actually, the block is removed once but it gets placed again even if the block you look after breaking the block is air block.
I'm not good at English so I provide a video to show the glitch.
Linked issues
is duplicated by 5
MC-147620
Odd block placement behavior when breaking and placing at the same time
Resolved
MC-160928
Breaking and Placing floating blocks
Resolved
MC-171718
Floating blocks are replaced with held block when both mouse buttons are used simultaneously in creative mode
Resolved
MC-173955
The wood placement changes without placing on a block
Resolved
MC-230349
being able to place blocks where respawn anchores exploded
Resolved
relates to 4
MC-263176
You can make glitched bamboo by just right-left clicking at the same time
Open
MC-159145
Breaking and placing a block at the same time can place the block in the incorrect direction
Open
MC-172384
Double slabs can be placed accidentally when clicking too fast
Open
MC-172069
Piston arms are not deleted when the base of a pulsing piston is replaced with another piston
Resolved
As far as I have understood, this is a feature, not a bug.
Edit: and I mean like facing hoppers on Y 0 facing down.
Not something like having a issue with blockstates (like dispenser being powered all the time)