System Information
Operating system: Windows-10-10.0.19044-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 517.40

Blender Version
Broken: version: 3.3.0, branch: master, commit date: 2022-09-06 15:39, hash: rB0759f671ce1f
Worked: (newest version of Blender that worked as expected)

Short description of error
Keyframing Offset Factor (under "Follow Path" Object Constraint) when using a curve object as target works fine. But...

After adding "Follow Path" Object Constraint, onto a sphere with the target curve (converted into a curve from duplicated and separated vertices from a mesh object) and when trying to keyframe Offset Factor by clicking the diamond box,

1. it gives the Report Error message.
2. Then when my mouse hovers over other keyframable things on the Constraint options, it auto-keyframes.

Exact steps for others to reproduce the error

1. Create a curve by (duplicating a series of vertices from pre-existing mesh, Separating it, then Converting it to a Curve object).
2. Create a sphere mesh.
3. Add object Constrant on the sphere, and target the curve. Check: Fixed Position, and Follow Curve on the Constraint options. Click Animate Path. (Forward axis: X, Up axis: Z).
4. Then click on the diamond keyframe button beside the Offset Factor in the Constraint option. It gives the "Report: Error... F-curve with path......." message. After, try hovering your mouse cursor over other keyframable options in the Constraint. It automatically keyframes, without my meaning to do so.