In Financial Gateway Manual Dispatch we are limited to 300 payments. Is there somewhere to change t

We are testing some new ACH PPD files.  We are importing from external flat files.  When we do the manual dispatch, we are limited to 300 payments.  Is there a way to change the limit?

Eventually we will schedule these dispatches, but are testing right now.   If there are 1700 payments, it shows 300 at a time and you click on select all, but it only selects the 300 it is showing.  I've tried paging down and selecting 300 at a time, but you lose the ones you marked earlier.

Any suggestions would be appreciated!  Thanks!!