Crossing FL E to W yesterday at 10k on an IFR FP. I notice a plane in opposite direction 10 miles out, 200 above. Panel starts barking. He passes 1 mile off my right wing, 200 above.
No call out from ATC. I wait a few mins and query controller. He says umm, "yeh sorry we are a bit behind the curve today, again I am really sorry"
Reminder is even on an IFR FP your life depends on the PIC to keep you safe. Can't rely on ATC, they are over worked, under staffed and not providing the same level of service some if us are used to paying for.