Operating system: Windows 10 Pro 64-bit (10.0, Build 17763)
Graphics card: NVIDIA GeForce 920M
Short description of error
The Bump Node in Cycles is inverted like a bug but the Bump Node in Eevee works very good.
Exact steps for others to reproduce the error
(All textures are packed into the .blend file)
Step 1: Open the .blend file.
Step 2: Switch to Rendered, then you remark that the bump has no bug because it's in Eevee.
Step 3: Now, switch to Cycles Render Engine, then you remark that the bump (X) is inverted, and that's the bug.
I complicated the object into a round object in order to see well the object shading compared to the bump shading.