DRV8825: the discontinuity of the current with phase B

Tool/software:

hi,

a my account meet a abnormally stop rotating issue with DRV8825,the discontinuity of the current with phase B is captured. The schematic and waveforms are in the test report.

what are possible reasons to lead the discontinuity of the current with phase B ?

e2e.ti.com/.../the-discontinuity-of-the-current-with-phase-B-.pptx