just wanted to offer my experience. I had the exact same issues to the point my clutch was barley grabbing at all meanwhile 30 seconds prior to this sudden broken clutch i was going thru all gears no problem. After making it home that specific ride it no longer grabbed thus would not move an inch forward and would not stall out no matter what I did. Somehow someway 2 weeks later after letting it just sit I started it and let go of the clutch to have it drag me by my arms into a table and several other cluttered basement items. After I adjusted my clutch to what felt perfect I was able to switch all gears and enter neutral while at a stand still or with the bike turned off. it has been flawless since. point being the clutch is sensitive to the adjustment and needs tinkering as once its warm it becomes looser/tighter. just need to have it adjusted right.

Mine seems impossible to get in neutral when running and hard/impossible to upshift at standstill.
I'm still figuring out adjustment on clutch I guess. It seems to go through gears good going down the road.

You have to use mineral based oil for the break in. The synth oil will cause clutch issues.

Think of two pieces of glass with water between. Now think of the same two pieces of glass with BB's between. Synthetic oil and mineral oil have different molecular structure, the synth being a much more uniform and fine, the mineral with a more coarse shape.

Some clutches will never work with synth oil. My Husky used to give me a fit with synth oil, now I use a blend and it is fine.

What I would do is drain most of the oil, and fill back up with a good auto trans fluid and run for a brief time. Work and slip the clutch to deglaze and clean it out. Then drain and fill with a good mineral base oil for motorcycle.

I think it should be set to 10 - 20 mm of free-play on the clutch cable