Look at the project's Free/Busy badge on its card - if it says Busy, someone is working on it right now.
Each project has a single Free/Busy state shared across every PC and person. When a work session starts the project turns Busy; when it ends with a changelog it goes back to Free. Because the state belongs to the project itself, you see the same thing whether you are on your machine or a teammate's.
What Busy tells you
- Who holds the session right now.
- What they are doing - the session's objective.
- When it is expected to free up.
A project allows one active session at a time, so if you try to start while it is Busy, SyncNow tells you the project is taken and asks you to wait. If you need it sooner, coordinate with whoever holds it - and a stuck session can also be revoked - then the project flips back to Free for everyone.