Nope, no one has reported this, so it seems the error lies on your side somewhere.
Have you tried the trusted ' clear cache and cookies' sometimes even switching off your device completely and switching back on, works.
Which browser are you using ? Chrome works best with eBay.
If you are not seeing ' Sent Messages' these are now incorporated with your messages received, just scroll down the received message, and you'll see the message you sent in reply.
@dispairsquid
