I recently upgraded from Elements 10. Artist 11 does not record midi although Elements 10 continues to record midi. Artist 11 will play the midi projects recorded in EL10 but not record on those tracks. The indicator light shows midi signal in and all the ports are active and correct.
Double check the Preferences > MIDI > MIDI Filter, please. Make sure Notes are not filtered out.
Also double-check, you are not using your MIDI device as an input of any remote device in the Studio > Studio Setup, please.
Could you try in Cubase Safe Start Mode [Disable preferences], please?