Everything is now nearly working. The response from the M280 commands are as expected. However the probe status remains fixed at activated - it doesn't change regardless of any instruction.
I imagine I've got a configuration issue relating to the BLTouch sensor but have so far failed to identify what the issue is. I have tried changing the options relating to ENDSTOPPULLUP_ZMIN, Z_MIN_PROBE_ENDSTOP_INVERTING, Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN, Z_MIN_PROBE_ENDSTOP but the sensing remains fixed at selected.
I imagine I've got a configuration issue relating to the BLTouch sensor but have so far failed to identify what the issue is. I have tried changing the options relating to ENDSTOPPULLUP_ZMIN, Z_MIN_PROBE_ENDSTOP_INVERTING, Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN, Z_MIN_PROBE_ENDSTOP but the sensing remains fixed at selected.