DataGridView keeps making headers bold when GroupBox is bold?

I have 2 sets of GroupBoxes with a DataGridView in each one of them on a Windows Form. I have one set to where the DGV column headers are NOT bold regardless is the GB is bold or not.

For some reason I can't get the other one to act the same way.

In design mode, I basically make the GB bold, then, for the DGV, I set the "bold" property to False for the "ColumnHeadersDefaultCellStype", "DefaultCellStyle" and "RowHeadersDefaultCellStyle". Once that's done, I go back and set the GB's "bold" property to False. This still isn't working and I have no idea what else to do.