When you are mining a tree from underneath (as shown below) with an axe, the cracking effect shows as you would expect.

However, when mining a block of tree from the same position without any tools, the cracking effect glitches and after 4 blocks, the cracking effect doesn't show at all. For this bug to work, you have to be directly underneath the block with your mouse going as far up as possible on the screen (looking directly up to sky). The cracking effect does show with an empty hand once you have come off this direct up position.
I can confirm that this isn't my computer or any of the other mods I have installed (I have optifine and even without optifine and on default texture pack, the same bug occurs).

(Please see photos below which include two version- one with optifine and Resource pack, and the other without optifine and default resource pack).