G29 Bed Level not doing anything on Marlin 2.0
From the linked Configuration.h file the probe X, Y, Z probe offset is set by constant array:

#define NOZZLE_TO_PROBE_OFFSET { 75, -35 , 0 }


So, the sensor is mounted at the right-front (X+, Y- according to the Marlin configuration definition) when facing the printer.

This implies that the sensor is limited on the right and at the front.

The probing area used to be defined in Marlin 1.1.x in the Configuration.h file. However, Marlin 2.x requires edge offsets rather than absolute bed size constraints. From the Configuration_adv.h of linked file, the following probing limits are set:

#if PROBE_SELECTED &amp;&amp; !IS_KINEMATIC
  #define MIN_PROBE_EDGE_LEFT (75 + MIN_PROBE_EDGE)
  #define MIN_PROBE_EDGE_RIGHT (X_BED_SIZE  - MIN_PROBE_EDGE)
  #define MIN_PROBE_EDGE_FRONT (MIN_PROBE_EDGE)
  #define MIN_PROBE_EDGE_BACK (Y_BED_SIZE -35 - MIN_PROBE_EDGE)
#endif


This is incorrect, this is what you would do in Marlin 1.1.x. Note that this answer describes in detail how to set the bed probing limits. You need to specify the offset from the edge on each side, in schematics the probing area is defined as:



From your printer configuration, the probing limits should be set to:

#if PROBE_SELECTED &amp;&amp; !IS_KINEMATIC
  #define MIN_PROBE_EDGE_LEFT (75 + MIN_PROBE_EDGE)
  #define MIN_PROBE_EDGE_RIGHT (MIN_PROBE_EDGE)
  #define MIN_PROBE_EDGE_FRONT (MIN_PROBE_EDGE)
  #define MIN_PROBE_EDGE_BACK (35 + MIN_PROBE_EDGE) ; Note that 35 is absolute(-35)!
#endif