Cannot get a formula array to return the correct count of list items

I have an array formula that extracts sequences and start time periods eg "1A, 2A .. 3B" (from the data block starting at G2 in the attached ) I have managed to compose a formula array that extracts the data required and places it at D17:D28.

What I can't fathom out is how to extract this data only when column G contains say "R4". Can it be done?

Sorry if this is not clear hope the attachment helps . The red fill shows the data.It would appear that the repeating sequence at row 103 is not picked up when the "R4" search is introduced.

The first formula

=SUM(((($H$3:$U$848=$C$4)+($H$3:$U$848=$D$4)+($H$3:$U$848=$E$4))*($I$3:$V$848=$C$6)*(($J$3:$W$848=$C$8)+($J$3:$W$848=$D$8)+($J$3:$W$848=$E$8)))*(($H$4:$U$849>=$Z3)*($H$4:$U$849<($Z4))))

works fine

The second

=SUM(((($H$3:$U$848=$C$4)+($H$3:$U$848=$D$4)+($H$3:$U$848=$E$4))*($I$3:$V$848=$C$6)*(($J$3:$W$848=$C$8)+($J$3:$W$848=$D$8)+($J$3:$W$848=$E$8)))*(($H$4:$U$849>=$Z3)*($H$4:$U$849<($Z4)))*($G$3:$T$848="R4"))

fails
when I add in

*($G$3:$T$848="R4")

Thanks for reading this far