When clothing data is applied before painting the influence on the section the cloth doesn't simulate.
I tested this using the Paragion: Twinblast actionhero skeletal mesh asset.
Found in 4.24.1 CL#10757647
Reproduced in 4.25 Main CL#11033263
1. Import a skeletal mesh that has a section that can be used for cloth simulation.
2. Make sure there is no clothing data applied to the skeletal mesh.
3. Create clothing data based off of the section.
4. Apply the clothing data to the section. Don't paint the section before doing this.
5. Paint the section so the skeletal mesh should simulate.
6. Test the cloth simulation in a scene.
Result: The cloth doesn't simulate.
Expected: The cloth simulates as expected.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-87003 in the post.