I have a 2006 Volvo V70.
When I was driving yesterday, the car displayed a notification that the oil level was low and I should top it off. Since this was a non-urgent notification (as opposed to a warning that needed to be dealt with immediately), and it was only about low oil level, not low oil pressure, I dismissed it and stopped on the way to purchase some extra oil of the correct type. The notification persisted through multiple engine restarts and it originally came on when driving straight ahead on a fairly level road.
Today, with the car having been sitting on level ground over night, I went out to top off the oil. However, checking the measurement stick (twice!), the oil level was right at the top of the recommended range. The notification is also gone, even after driving about 20 km. I did remove the cover where you're supposed to add oil and immediately put it back on, but never added any oil. To me the cover felt firmly, but not excessively tightly, screwed on.
What might have happened? What might reasonably cause the car to consistently report a low oil level, followed by no such report, when there is clearly a sufficient amount of oil in the engine after it's been sitting for a while? Could the oil filter be clogged? From looking at my notes, it looks like the oil filter was most recently changed this June, and I've driven the car about 4500 km since that service was performed. The oil that was put in at that time is given as 0W-30Ti EE PrA5, and I typically drive about 10000 km per year.