Hi There id say your looking at the wrong window I had the same problem . When the bike is on the main stand theres something that looks like a oil window (same shape) but the sight window is actually behind the side stand ( as in you can't see window unless side stand is down out of the way of glass. Hope this helps Let me know how you get on . it should take 2.8 lts of oil without filter replacement
2.9 lts if you change oil filter .