Oil filter adapter O-ring

[GT80]

I saw someone mention this in another thread but they never got any feedback. I bought the Felpro OS34500R oil pan gasket and it came with a new o-ring for the oil filter adapter. Same diameter but almost 3x as thick. It also came with a round o-ring that's the same diameter and similar in thickness to the original "square" one. Is this what they intend for you to use? That thick one can't be right.

 

[GT80]

The guys at NAPA say it probably started it's life out as a round o-ring. Maybe that's it.