It sounds like you're violating the Excursionist Perk rules by trying force a stopover in the 2nd Region (we'll call that Region B) before continuing on to Manila (we'll call that Region C) instead of continuing back to the US (we'll call this Region A).
The E.P. rules are quite clear on what's allowed and if you follow them, you'll see that the E.P. is not defined by time of stay. These rules were changed in 2016, so you may not be familiar with them:
MileagePlus Updates - Booking award flights