Richard, this is your exact code (no changes at all) and it lights the LED steady ON:
Code:
' PIC 16F18446
#CONFIG
    __config _CONFIG1, _FEXTOSC_OFF & _RSTOSC_HFINT1 & _CLKOUTEN_OFF & _CSWEN_ON & _FCMEN_ON
    __config _CONFIG2, _MCLRE_ON & _PWRTS_PWRT_64 & _LPBOREN_OFF & _BOREN_SBOREN & _BORV_LO & _ZCDDIS_OFF & _PPS1WAY_OFF & _STVREN_ON
    __config _CONFIG3, _WDTCPS_WDTCPS_31 & _WDTE_SWDTEN & _WDTCWS_WDTCWS_7 & _WDTCCS_LFINTOSC
    __config _CONFIG4, _BBSIZE_BB512 & _BBEN_OFF & _SAFEN_OFF & _WRTAPP_OFF & _WRTB_OFF & _WRTC_OFF & _WRTD_OFF & _WRTSAF_OFF & _LVP_OFF
    __config _CONFIG5, _CP_OFF
#ENDCONFIG


' ====== DEFINES ===================================================================================
    DEFINE OSC 4
    ANSELB = $B0;
    OSCCON1 = $60; // CSWHOLD may proceed; SOSCPWR Low power;
    OSCCON3 = 0;  // MFOEN disabled; LFOEN disabled; ADOEN disabled; SOSCEN disabled; EXTOEN disabled; HFOEN disabled;
    OSCEN = 0 ;    // HFFRQ 4_MHz; 
    OSCFRQ = 2;  // HFTUN 0; 
    OSCTUNE = 0


' ====== TEST PROGRAM ==============================================================================
TEST:
    TOGGLE PORTB.6
    pause 500
GOTO TEST
END

Unfortunately, the third example dosen't work either, this one:
Code:
' PIC 16F18426
#CONFIG
    __config _CONFIG1, _FEXTOSC_OFF & _RSTOSC_HFINT1 & _CLKOUTEN_OFF & _CSWEN_ON & _FCMEN_ON
    __config _CONFIG2, _MCLRE_ON & _PWRTS_PWRT_64 & _LPBOREN_OFF & _BOREN_SBOREN & _BORV_LO & _ZCDDIS_OFF & _PPS1WAY_OFF & _STVREN_ON
    __config _CONFIG3, _WDTCPS_WDTCPS_31 & _WDTE_SWDTEN & _WDTCWS_WDTCWS_7 & _WDTCCS_LFINTOSC
    __config _CONFIG4, _BBSIZE_BB512 & _BBEN_OFF & _SAFEN_OFF & _WRTAPP_OFF & _WRTB_OFF & _WRTC_OFF & _WRTD_OFF & _WRTSAF_OFF & _LVP_OFF
    __config _CONFIG5, _CP_OFF
#ENDCONFIG


' ====== DEFINES ===================================================================================
    DEFINE OSC 4
    ANSELC = $DF;
    OSCCON1 = $60; // CSWHOLD may proceed; SOSCPWR Low power;
    OSCCON3 = 0;  // MFOEN disabled; LFOEN disabled; ADOEN disabled; SOSCEN disabled; EXTOEN disabled; HFOEN disabled;
    OSCEN = 0 ;    // HFFRQ 4_MHz; 
    OSCFRQ = 2;  // HFTUN 0; 
    OSCTUNE = 0


' ====== TEST PROGRAM ==============================================================================
TEST:


    TOGGLE PORTC.5
    pause 500
    
GOTO TEST
END

Maybe this last code doesnt work because you seem to use a 16F8246 not a 16F18446 like I have.

Honestly, I can have a real good life with LATBs commands instead of TOGGLEs