Weird, your recomended 4 dimm config differs from gigabyte guidance.
GIGABYTE: CD + HG ( same for board with 16 dimm slots)
your source: AC + EG
Maybe gigabyte is older guidance that assumes half of the chiplets on cpu (ie up to 32 core config)? That would explain the asymetry. Testing is required.
Either way, OP has ABC F socketed, which is likely wrong config when taking in account either guidance. Reshuffling and testing configs via memtest is probably easiest fix on OPs side.
EDIT: there is older thread about this board and memory issue here on l1techs too. Good reference point.