Thanks for the thorough testing with the different strings on local vs remote. That’s a clean way to isolate the problem.
This does look like a bug in how subagent definitions are resolved during Remote SSH sessions. We have a few related reports from WSL users experiencing a similar local-vs-remote path mismatch (Subagents in WSL), and our team is actively working on improving Remote SSH context handling more broadly.
For now, the workaround is to edit your subagent files directly on the remote host (since that’s what the runtime reads), and treat the Settings UI listing as unreliable when connected via SSH.
Also worth noting: you’re on version 2.6.20, which is a couple months old. Updating to the latest stable may help, as there have been several Remote SSH improvements since then.
We’ll update this thread when there’s a fix for this.