Hi Amit,
Please check if you have written any CMOD/BADI enhancement for 2LIS_13_VDITM in R3 system.
it might be the reason records are filtered out due to code logic.
Second check , please identify, docs are missing for which Sales Org. , Plant and then go to detail level,
It might be you forgot to put that sales org, plant at the time of Full load(Setup table fil up)
if this is the case then you need to do full repair for that sales org..
third check..if you have put any filter for Sales org or plant . sales org. or plant for missing doc. are missed in info package filter(data selection).
Regards
Atul