Measure group partition rows keep growing during processing

Hi all,

I have a working SSAS previously with processing duration around 3hr+ until one weeks ago, it had process issue. Error log stated that it's timeout where the ExecCommnadTime I had set to 21600 (6 hours). I found out that the one of the Measure group's partition with total rows read result abnormally. The total rows it read has like 10 times more than the actual result. The partitions i set is using query binding with WHERE clause to split the DateKey of data.

Need your advice on this issue. In what condition will cause this kind of issue normally? Thanks in advance!