I've tried applying some criteria, but the row is still there.
This first empty row shouldn't be there.
Here is the formula, in case you'd like to help me correct it:
=if(I4<>"", { IFERROR(query(Datasets!X3:AU,"select AS, AT, AJ, AR where AS matches date '"&TEXT(DATEVALUE(I4),"yyyy-mm-dd")&"'",0),{"","","",""}); IFERROR(query(Datasets!BC3:BT,"select BC, BD, BS, BQ where BC matches date '"&TEXT(DATEVALUE(I4),"yyyy-mm-dd")&"'",0),{"","","",""}) }, UNIQUE({query(Datasets!X3:AU,"select AS, AT, ' ', SUM(AR) where AS is not null group by AS, AT, ' ' label ' '' ', SUM(AR) ' '",0); query(Datasets!BC3:BT,"select BC, BD, ' ', SUM(BQ) where BC is not null group by BC, BD, ' ' label ' '' ', SUM(BQ) ' '",0) }))