Try to find it like a buyer would. And CAN'T!
Then go to my store and find it.
Then back to a normal search and NOWHERE TO BE FOUND
Then end up finding it way down in "results matching fewer words"
Even though it's EXACTLY what I searched word for word.
I have seen that happen. Not often, thankfully, but it does certainly happen.
I suspect that there are some inconsistencies with how eBay treats certain combinations of keywords that often appear grouped together. Sometimes it seems that a group of keywords can be treated as an entirely independent keyword, distinct from the individual keywords that comprise it. So searching for the individual keywords out of order may not match the "group" keyword. Either that or the keyword substitution feature has some serious one-way mapping issues, where cap matches hat, but hat does not match cap. I do not have enough data to draw a firm conclusion, though, because the problem seems pretty rare, as far as I can tell.
If you notice that happening when you search for your item, I would suggest looking at some of the results that appear in the search proper above those "matching fewer words" results, if there are any appropriate matches, and to try making your title more closely match one of those successful listings in terms of keyword order. That may bypass the grouping issue.
That same strategy may help with the "Price plus shipping: lowest first" sort order filtering issue as well.
