[Cause]
At the start of or during brake diagnostics, the dual-drive pair of the displayed group was already in dual-drive pair adjustment mode. ($DUAL_DRIVE[group number].$ADJUST_SEL[dual-drive pair number] has not yet become zero.)
[Countermeasure]
After dual-drive axis adjustment mode is finished ($DUAL_DRIVE[group number].$ADJUST_SEL[dual-drive pair number]=0), execute brake diagnostics again.