Hey, thanks for the detailed report. The environment info, logs, and what you already ruled out really help.
This is a known issue we’re tracking. On 3.15.x, remote hosts on older kernel or glibc, in your case CentOS 7 / kernel 3.10 where the server uses the linux-legacy-x64 build, can crash the remote extension host. That makes Agent or Composer time out, while local editing and the terminal keep working. The same behavior was reported on Debian 9 here: Regression in Cursor 3.15.6: Remote SSH Extension Host crashes with SIGSEGV on Debian 9 (linux-legacy-x64)
Your workaround is the right call. Stay on 3.14.27 until there’s an update. Everything you tried, wiping ~/.cursor-server, deleting state.vscdb, tweaking remote.SSH.connectTimeout, won’t help here. And you were right to rule out the sandbox preflight. It’s not related to this timeout.
I can’t share an exact timeline yet, but I’ll post in the thread as soon as we have an update. Thanks again for laying it all out so clearly.