Hi Alex,
Not clear whats your facing. am guessing like your extrators may not pulling data into bw but ecc have data. if yes then while loading data from ecc to BW, please check the job log details at ECC Sm37.
copy the request id from BW info pack monitor --> header tab.
go to ECC tx - SM37, job name : BI<copied req id from bw>, user id: *
date: aug 6 to aug 7.
status : active,cancel and finish.
You will get respective job, select that one and click on job log details.
Even you can check the ecc Tx - SM58, queue may stucked.
Take basis team help. if see any red at SM58.
Even check about authorisation roles(NEW_ALL, S_BI-WHM_RFC and S_BI-WX_RFC) to extract data from ecc to bw.
Thanks