Like the title says, sometimes the mod gives you step-up without cyberlegs being installed. It happens when deployable wheels are turned on in one world and you switch to a different world where you may not even have cyberlegs installed, but you can still walk up full blocks. Reloading minecraft always fixes the issue.
Steps to reproduce:

1. Install the mod.
2. Make two new worlds. I'll call them New World 1 and New World 2. Don't enter New World 2 yet!
3. Go into New World 1 and install cyberlegs, a power source, a battery and deployable wheels.
4. Turn deployable wheels off using the cyberware menu, then attempt to walk up full blocks. You can still walk up blocks even though deployable wheels are turned off and don't draw power.
5. Save and close New World 1. Then enter New World 2. Despite not having any cyber augments, you can still step up blocks.

Forge 14.23.5.2855
Cyberware 1.12.2-0.2.11.29

Addition: this also affects the cyberware menu. You can't turn deployable wheels off. The menu will indicate that it's off, it no longer draws power, but you can still step up full blocks. It will only turn off after restarting minecraft.

You're probably switching between a modded and non-modded world through a proxy. This isn't supported by forge mods and leads to many such desync. Until a proper API is provided for it in Forge, it won't be fixable. Flight as the same issue.

No, that's not the issue. I didn't even know that's a thing and certainly wouldn't try something like that. I'll test it properly within a clean environment with only Forge and cyberware installed.
EDIT: still happens with only cyberware installed. I'll add steps to reproduce.

Has the issue been tested? It still has the won't fix label. I've added steps to reproduce it.