There are different default M307 parameters for H0 and for the other heaters, because H0 is assumed to be the bed heater. So you will need to change the M307 H1 parameters to suit a bed heater, and the M307 H0 parameters to suit an extruder heater. To find the defaults, boot up your Duet with the SD card removed, then send M307 H0 via USB or PanelDue, followed by M307 H1.