How to reproduce:
1. Create a new project
2. In the project, install the “com.unity.ai.assistant” package
3. In the Assistant window, enter a prompt using CJK characters
4. Attempt to enter another prompt using CJK characters
5. Observe the Console and Assistant windows

Actual result: ArgumentOutOfRangeException is thrown in the Console and input into the Assistant window stops working
Expected result: Prompt input is accepted and no errors are thrown

Reproducible with: 1.0.0-pre.2 (6000.2.0a9), 1.5.0-pre.1 (6000.3.5f1, 60004.0b5, 6000.5.0a4)
Could not test with: 6000.0.66f1 (AI Assistant is not supported)

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Note: Tested using Korean and Japanese languages