Diagnostics shows the current health of the pieces your account depends on — background job processing, recent sync activity, and similar system-level signals.
If something in your account seems stuck (submissions not arriving, exports not generating), check this page first. If it shows a problem, mention what you saw here when contacting support — it saves a back-and-forth. If it looks healthy but something still seems wrong, the issue is more likely specific to your data, so contact support directly.