Instant mining blocks in cobwebs does not always work

When the player is partly or fully in a cobweb and tries to instant mine, for say dirt or gravel in a trail ruin, it may not work, may not work and play the break sound twice, and when it doesn’t work, it shows it breaking then returns the block, not a ghost block. Doesn’t seem to act the same when the blocks are placed again on the same place, feels like a dice roll when it occurs. I am playing in an older single player world, pure vanilla

What I expected to happen was...:
The instant mine-able blocks to break

What actually happened was...:
Some times it breaks it, sometimes it shows and plays the sound but returns the block, other times it does as before but plays a double sound.

Steps to Reproduce:
1. Place a cob web and have the player stand in it, it doesn’t matter if it’s at the foot, the head block or if the player is partially in a cobweb
2. Have blocks and an appropriate tool that can instantly mine a block, for say an efficiency 5 shovel on dirt
3. Mine the appropriate blocks with the tool and observe