Causes for Cash Receipt Batches [RB] having the header posted and details only partially posted

E1 FIN Receivables experts,

Does anyone have ideas for me to suss out root cause of many batches (several a week) where the Batch Header is Posted [F0011] and the Details [F03B14] are "P" rather than "D".

We run the R007021 every week, but they are not looking at this faithfully.

Thanks in advance for any suggestions,

PattieK