Configure the following settings in [Advanced Settings] for the custom paper you are using.
<Printing in black and white>
Increase the value in 029: [Paper Transfer Current: B&W: Side 1] or 030: [Paper Transfer Current: B&W: Side 2] by -20 A.
Eg., -100 A to -120 A
<Printing in full color/Printing in full color including the clear toner while the special color is not set to high quality>
Increase the value in 035: [Paper Transfer Current: FC: Side 1] or 036: [Paper Transfer Current: FC: Side 2] by -20 A.
Eg., -100 A to -120 A
<Printing in full color including the clear toner and the special color is set to high quality/printing in full color including the white toner>
Increase the value in 037: [Paper Trnsfr. Current: FC: Side 1: Qual.] or 038: [Paper Trnsfr. Current: FC: Side 2: Qual.] by -20 A.
Eg., -100 A to -120 A
After performing the solution, it is recommended to perform the color calibration of the external controller.