When I go into record and play the notes, they appear as red for a few seconds after I hit stop, and then disappear. I can hear them in playback, but cannot find the notes in PRV, and I've done everything I know to do to make sure I'm in the right PRV. The notes I play while in record sound off in playback but don't appear in the PRV. The notes I create manually in the PRV are visible and normal looking, but don't sound off.

The Step Sequencer option is greyed out, maybe that's a clue, but I don't know what it means.
 

I don't know what icon you're referring to... there is only one, that looks like a grid, I've manipulated the options it offers but it doesn't seem to make a difference in my issue. The only way I know how to hide notes is the "Notes" pull down menu, where there is a "show notes" toggle... it is toggled to show.
 
I get to the PRV by right clicking on the track I'm trying to work with, and it is labeled correctly at the bottom of the PRV.
 

I do see input represented in Track view, though it looks different than what I'm used to. It's a continuous purple line that gets thicker where notes are played, instead of the dashes I'm accustomed to. This a SD3 folder I'm working in.
 

This has actually become stranger. This in an SD3 folder, and I've done it this way many times before. I notice when I put the track in record and actually play notes in from the keyboard real time, they show up in the PRV as pale red squares that last for a few seconds after I hit stop, then they disappear. They sound off in playback, but I can't find those notes again to manipulate. I can still add notes manually, and they appear normal, but do not sound off. The note representation in Track view is different as well, it manifests as a purple line that gets thicker where notes are played instead of the dashes I'm use to seeing.
 

That's how I always get to PRV, and the PRV is labeled correctly to the track I'm working with.
 

Maybe you have more than one track selected in PRV and the one you're recording is being covered up by another.
 

Give a step by step on how you are doing this. Start from the very beginning. For example I record enable track 10 then....

Perhaps the note durations are so short that they are hard to see or aren't being drawn correctly? Can you see them in the event viewer? What are the durations there?

You guys might be right, I was opening the PRV right clicking on the specific instrument, in this case Percussion 2 in Session Drummer 3, instead of the SD3 midi row at the top... the notes show up there. Although, this still seems strange to me, I've done this quite a bit and I'm used to having the keyboard representation to the left instead of just the instrument list. Maybe I'm misremembering.