Same problem here with LATAM. Some posted, some not (oldest from December). More strange is that all bookings were for 2 persons and for some flights my partner got the credits on FinnairPlus straightaway whereas I had to claim. And have been waiting and waiting.
Generally my experience is that flights from LATAM and SriLankan do not post spontaneously.

I moved to Finnair Plus a year ago as it appeared to be the best program for my travel pattern. But I regret it already as I now have to maintain a complete boarding pass administration system. Compared to my Flying Blue (automatic credits within 2-3 days, if any claim is ever submitted it is followed up within 1 day) and Turkish Miles and Smiles (TK flights credited same day, partner flights within 1-2 days, do far not any claims needed to be submitted), Finnair Plus comes across as a not very solid program.
It annoys me as I have better things to do than dragging boarding passes halfway across the world while travelling.