Well, I made a mistake that cost me some time and brain cells, but fortunately not a lot of $. I decided to write a post so that others might be helped, despite my embarrassment. :/
I did the oil change including the filter on my 2015 5.0 about 3 months ago. The car began leaking oil recently. Up on the jacks, covers off, & the oil is seen seeping from the oil filter cannister where it (the plastic cannister) contacts the metal housing that it threads into. Long story short, in a bit of a rush and not paying close enough attention (the enemy of all who work on their own car) I left the old, flattened oring in place when I did the previous oil change. It can be hard to see when it's flattened and your eyes are 60+ like mine. I also, at the same time placed the new oring in an incorrect spot, which looks like a willing circumference, near the end of the plastic cannister. This arrangement (old and misplaced new oring) was good enough to hold off a catastrophic leak, but not enough to prevent a slow leak which saturated the front undercover and a bit of the rear undercover. After a while the excess oil began to drip off the undercover. It took a while and a few cannister removals / installs for me to see the extra oring on the cannister and fix the problem. Arrrgh. I hope this helps someone!
I did the oil change including the filter on my 2015 5.0 about 3 months ago. The car began leaking oil recently. Up on the jacks, covers off, & the oil is seen seeping from the oil filter cannister where it (the plastic cannister) contacts the metal housing that it threads into. Long story short, in a bit of a rush and not paying close enough attention (the enemy of all who work on their own car) I left the old, flattened oring in place when I did the previous oil change. It can be hard to see when it's flattened and your eyes are 60+ like mine. I also, at the same time placed the new oring in an incorrect spot, which looks like a willing circumference, near the end of the plastic cannister. This arrangement (old and misplaced new oring) was good enough to hold off a catastrophic leak, but not enough to prevent a slow leak which saturated the front undercover and a bit of the rear undercover. After a while the excess oil began to drip off the undercover. It took a while and a few cannister removals / installs for me to see the extra oring on the cannister and fix the problem. Arrrgh. I hope this helps someone!