After adding this into a modpack, it seems as though
even mining stone creates a 'felling' effect,
while digging a block that has more blocks connected above it.
I did search for this similar problem, but haven't found any similar issues so I thought of writing this down~

I found this issue is caused by the Physics Mod, specifically-
( https://www.curseforge.com/minecraft/mc-mods/physics-mod/download/3633780 )

Using a CurseForge 1.16.5, Forge 36.2.20 client, this is what I have tried:

🔘 Created a fresh modpack, and adding only

physics-mod-2.6.7-mc-1.16.5-forge
(Blocks did not collapse)

🔘 Created a fresh modpack, and adding only
TreeChop-1.16.4-0.14.6-fixed
(Only logs collapse)

🔘 Created a fresh modpack, and adding only both,
Default config and settings replicate this bug.

🔘 Changed the config settings relating to felling and chopping to false

🔘 Used the keybinds in-game to toggle felling and chopping off

Result: Despite the features being toggled false, breaking any block seems to make it break those above it.
Interesting enough, breaking the nether roof's bedrock is also possible from this.

Hope this was at least a little bit helpful.
I'm just happy that it doesn't crash anything~

Edit: This was due to a config in the Physics mod that had updated. Woop. ---Nothing happened here--