Background terminal commands hang indefinitely in Codex sandbox.

Question

### What version of Codex CLI is running?

codex-cli 0.128.0

### What subscription do you have?

Pro Lite

### Which model were you using?

gpt-5.5 high

### What platform is your computer?

Linux 6.18.18-1-MANJARO x86_64

### What terminal emulator and version are you using (if applicable)?

Warp  v0.2026.04.27.15.32.stable_03

### What issue are you seeing?

Even trivial commands such as `pwd` and `true` never complete through the normal background terminal path. MCP was disabled. The same `p