MetropolisLust

I've replicated this issue in a normal world, heres how:

Step 1

Create this world:

seed: -8153867672389181665 on  1.16.1 (that the seed for my survival world where i experienced the issue, the version is the version when the chunk where the bug is occurring generated) everything else default

Step 2

 Tp to -232 68 -63 in the world whilst on 1.16 to generate the chunk, if your in a flower forest above a small lake thats correct
After that close the world, don't place or break anything.

Step 3

load up version 2.21

cover the lake with grass blocks, try not to misplace blocks on top of that layer

Like so, then bonemeal it and witness the bug

I also own this mouse, as soon as I update to 1.20.6 from 1.20.1 I started experiencing this issue.

At first I though an issue with the scroll sensitivity but I discover that the left and right buttons on the scroll wheel cycle the hotbar in the corresponding directions.

I assumed new key binds were made in the update but upon further investigation the minecraft control keybind config can't recognize these buttons. 

Although it might be an issue with this specific mouse, something in minecraft clearly has changed.