Thanks for taking my phone call this afternoon regarding this and then subsequently confirming that a Mahle branded oil filter with part number OX128/1D was supplied.
I can confirm that this is indeed the correct oil filter for all models of 986 Boxster 2.7L engine. (In fact it's compatible with all models of 986 Boxster.)
If you are able to provide photos of your current oil filter and it's installation, we will be able to advise further on how to fit the filter that we supplied.