Encoder on M1 not working

#1

I can’t get the encoder on M1 to work. The same encoder, motor and wiring work on M0. I have traced the fault to M1_ENC_B. There is no continuity from R33 to PB7, the board is v3.5. What can I do to find where this is happening and how do I rectify it?

axis1
axis: Error(s):
ERROR_ENCODER_FAILED
motor: no error
encoder: Error(s):
ERROR_NO_RESPONSE
controller: no error