RXP plugin menu -> Settingsl: Locked device settings

RXP-GTN750:
Problem:
- Bendix King KAP140:  when clicking NAV pushbutton, the NAV mode does not engage.

Additional info:
- XP12 version 12.1.2-R2
  AirfoilLabs C172NG ANALOG version 1.0.4

- XP12 ->  Reality XP plugin menu  -> Settings:   Settings panel shows all "Locked device settings". Unable to access any Panel Instruments or Device Options.

- With the default GNS530, no problem, I am able to Arm NAV and Engage NAV.
- Re-installed Reality XP_GTN750, but the problem remains.

Thanks in advance for any support,

Frank

RealityXP GTN ini file content:

[GTN]
; comma separated list of gauges
gauges = GTN_750_1

[GTN_750_1]
; comma separated list of read only settings.
locked = MasterDevice, NavDbType, HardwareDevice, HardwareIdx, LinkCrs, LinkObs, AutoNavGps, UseAudioPanel, UseTransponder, AutoGpsSource, AutoNavSource, AutoSavePln, LinkSimGps, LinkOto, LinkHsi, LinkVor, CopilotSide, AutoCdiSrc, RadiosPair, ComputerTime, CdiScale, GsiScale, UseAirData, UseFuelData, UseRyanTcad, RyanTcadVolume, UseTcadAiCount, UseFailures, UseSimGpsCmds, VFRmode, VFRcode, PowerSource, OwnshipIcon, FuelType, TawsMode, TawsSurface, TawsMinLength, TawsApprSpeed, TawsFlapSpeed, TawsGearSpeed, ReduceRate, Rheostat.Display, Rheostat.Buttons, VoicePref, MasterVolume, NoAudioFocus, CpuAffinity, AFMS.cdi_key, AFMS.sel_crs_gps, AFMS.sel_crs_vloc, AFMS.v_flag_declutter, AFMS.gps_selected, AFMS.auto_nav_appr, AFMS.airspace_labels, AFMS.mark_on_target, AFMS.rf_procedure_legs, AFMS.vnav_enabled, AFMS.vnav_trans_to_appr, AFMS.vnav_vdi_scale_factor, AFMS.vnav_trans_altitude
; comma separated list of render targets.
drawto = WINDOW, PANEL3D
; is the master device if true.
MasterDevice = false
; aviation db: 0: nav_db2_grm, 1: nav_db2, 2: nav_heli_db2_grmn, 3: nav_heli_db2
NavDbType = 1
; connects to: 'PFC_GTN' or any '#PID' (#D067 for PFC_GTN)
; no value connects to first found, 'OFF' disables connection.
HardwareDevice = 
; hardware selector number or -1 to disable.
HardwareIdx = -1
LinkCrs = true 
LinkObs = true 
AutoNavGps = false
UseAudioPanel = false
UseTransponder = false
AutoGpsSource = 1
AutoNavSource = 1
AutoSavePln = true 
LinkSimGps = true 

[GTN_750_1.WINDOW]
; display window if true.
visible = false
; show screen only gauge if true.
nobezel = false
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = WINDOW
; display position and dimension (left,top,width,height)
frame.rect = 1257,1890,830,692
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true 
; display mouse tooltips if true.
tooltips = false
; freeze display position if true.
locked = false
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = false
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true 
; display as popout window if true (requires XP11.1).
undocked = false
; VR mode position and dimension (left,top,width,height) (requires XP11.20)
vrmode.rect = 0,790,830,790
; auto hide in external view if true.
autohide = false

[GTN_750_1.PANEL3D]
; display window if true.
visible = true 
; show screen only gauge if true.
nobezel = true 
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = PANEL3D
; display position and dimension (left,top,width,height)
frame.rect = 1025,629,512,628
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true 
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = true 
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true 

[GTN_750_2]
; comma separated list of render targets.
drawto = WINDOW, PANELS
; is the master device if true.
MasterDevice = false
; aviation db: 0: nav_db2_grm, 1: nav_db2, 2: nav_heli_db2_grmn, 3: nav_heli_db2
NavDbType = 1
; connects to: 'PFC_GTN' or any '#PID' (#D067 for PFC_GTN)
; no value connects to first found, 'OFF' disables connection.
HardwareDevice = 
; hardware selector number or -1 to disable.
HardwareIdx = -1

[GTN_750_2.WINDOW]
; display window if true.
visible = true
; show screen only gauge if true.
nobezel = false
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = WINDOW
; display position and dimension (left,top,width,height)
frame.rect = 2536,1981,706,691
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = false
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true
; VR mode position and dimension (left,top,width,height) (requires XP11.20)
vrmode.rect = 0,395,415,395
; display as popout window if true (requires XP11.1).
undocked = false
; display mouse tooltips if true.
tooltips = false
; freeze display position if true.
locked = false
; auto hide in external view if true.
autohide = false

[GTN_750_2.PANELS]
; display window if true.
visible = false
; show screen only gauge if true.
nobezel = true
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = PANELS
; display position and dimension (left,top,width,height)
frame.rect = 0,0,0,0
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = false
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true