Hey, thanks for the report. This is a confirmed bug. If the model field has an invalid slug or a typo, Subagent will silently inherit the parent model with no warning. Slug matching is case-sensitive, so gpt-5.4-High won’t be recognized as gpt-5.4-high.
The team is aware of this issue. There’s no ETA yet, but your report helps us prioritize it. For now, the workaround is to make sure the model slug exactly matches what the model is called in Cursor, all lowercase.
Related threads if you want to follow along: