Kind of, it happened frequently when actually standing in a cobweb. In a quick test a preformed with mining 100 stone blocks standing in a cobweb, 43% of the stone did not get instantly mined with eff 5 haste 2. Another thing I just noticed is if you hold down right mouse button for break and try to break the stone, a lot more particles are produced and less of the stone was broken.
Also relates to MC-277337
Spawning on buttons and Redstone was deemed an intended feature, which is fine and can be fixed with slabs in a farm as intended, but just whether the scaffolding rule should apply here is up to a decision.