Run the bike parked on the jiffy stand with the oil tank cap off for 20 minutes, rev it, idle it, etc. Then stop the bike, shut it off, and install your dipstick/cap.
Level the bike upright.
Measure the oil level exactly then, hot, after running with the oil cap OFF.
Set your oil level to the middle mark on the oil cap.
Remember to always check the level HOT, and keep it exactly right where you set it (middle mark) forever.
Yes, it will sump when you park it for long periods, thus when you park it for a week or so, remove the oil tank dipstick/cap when you start it at home and let it run and get hot.
The vaccum caused by the tank not getting vented by the full of oil engine makes it hard for the oil pump to send it back into the tank. Vent the bitch by removing the oil cap, BUT DO NOT EVER ride it like that.
If it beomes a real pain, remove the oil pump check ball and spring and remove the check ball with a pen magnet, clean it with brakleen, and ever so slightly stretch the spring above the ball. SLIGHTLY!!!
Reinstall the ball first and then the spring and threaded cap with o-ring.
Done deal.
Yes, my beard has gray.
Or, you could be like the RUB that bought my pan that had this happen in winter after he parked it and sent it to a Las Vegas 'Ol School" bobber shop and they told him the engine was toast and he had to rebuild it. LOL!!!