[Bug] False positive validation error on legitimate API requests

**Bug Description**
improper flagging of legitimate request

**Environment Info**
- Platform: linux
- Terminal: xterm-256color
- Version: 2.1.268
- Feedback ID: ac2578b4-4066-424c-a11d-55a5ec4a8eaf

**Errors**
```json
[]
```

Start by reproducing the false validation error using the reported Linux environment, terminal, version 2.1.268, and Feedback ID. Trace the API-request validation path and identify the legitimate request that is being rejected; done means the request succeeds and a regression test covers it.

索引モデルが issue の本文から書いたものです。