Make sure Rescale Output is not checked on the Recording tab (or Streaming tab if using stream encoder) in Output.
When you play back the video in VLC what it the reported resolution? Tools --> Codec Information --> Video resolution:
Also, post a logfile from a live recording session at least 30 seconds in length. It will include your settings, so we can see if there's anything problematic going on (like 240fps recording).
Also, post a logfile from a live recording session at least 30 seconds in length. It will include your settings, so we can see if there's anything problematic going on (like 240fps recording).