SOLVED: Post #11 - IOC on negative edge sometimes triggers twice on single press

[Demon]

Any idea what's going on?

I removed the KHz variable and kept only MHz, but it still does the same thing:

- sometimes it triggers once,
- sometimes it triggers twice (IOC on positive edge is OFF),
- no pattern (that I could see),

16F18877

@ ERRORLEVEL -306   ; turn off crossing page boundary message
include     "C:\PBP Includes\DT_INTS-14_16F1885x-7x.bas"
include     "C:\PBP Includes\ReEnterPBP.bas"

ASM
INT_LIST  macro      ;IntSource,  Label,     Type, ResetFlag? 
        INT_Handler   IOC_INT,    _IOCinterrupts,    PBP,  yes   ;IOCC.3 
    endm
    INT_CREATE                              ;Creates the interrupt processor
ENDASM

#CONFIG
    __config _CONFIG1, _FEXTOSC_OFF & _RSTOSC_HFINT32 & _CLKOUTEN_OFF & _CSWEN_OFF & _FCMEN_ON
    __config _CONFIG2, _MCLRE_ON & _PWRTE_OFF & _LPBOREN_OFF & _BOREN_ON & _BORV_LO & _ZCD_OFF & _PPS1WAY_OFF & _STVREN_ON & _DEBUG_OFF
    __config _CONFIG3, _WDTCPS_WDTCPS_11 & _WDTE_ON & _WDTCWS_WDTCWS_7 & _WDTCCS_LFINTOSC
    __config _CONFIG4, _WRT_OFF & _SCANE_available & _LVP_OFF
    __config _CONFIG5, _CP_OFF & _CPD_OFF
#ENDCONFIG

DEFINE OSC 32

'   LCD is used for debugging
    
DEFINE  LCD_DREG      PORTD                 ' Set LCD data port
DEFINE  LCD_DBIT      4                     ' Set starting data bit
DEFINE  LCD_RSREG     PORTD                 ' Set LCD register select port
DEFINE  LCD_RSBIT     1                     ' Set LCD register select bit
DEFINE  LCD_EREG      PORTD                 ' Set LCD enable port
DEFINE  LCD_EBIT      0                     ' Set LCD enable bit
DEFINE  LCD_BITS      4                     ' Set LCD bus size
DEFINE  LCD_LINES     4                     ' Set number of lines on LCD
DEFINE  LCD_COM1MANDUS 1000                 ' Set COM1mand delay time in microseconds
DEFINE  LCD_DATAUS    50                    ' Set data delay time in microseconds

'   CCPx is used to control Contrast and Blacklight on LCD

define  CCP3_REG     PORTD                  ' PWM Pulse out to LCD contrast
DEFINE  CCP3_BIT     2                      '   2N2907 PNP with 1K on base
define  CCP4_REG     PORTD                  ' PWM Pulse out to LCD backlight
DEFINE  CCP4_BIT     3                      '   2N2222A NPN with 1K on base

IOCBP = %00000000                           ;IOC Interrupt, Positive Edge, low-to-high
IOCBN = %00000100                           ;IOC Interrupt, Negative Edge, from high-to-low

WPUB = %00000100                            ; Pull-up resistor on pin B2

'   PPS is used to move CCP functions to other pins

PinD2           CON $1A                     '    Datasheet table 13-2
PinD3           CON $1B
CCP3PPS = PinD2                             ' CCP3 Peripheral input selection
CCP4PPS = PinD3                             ' CCP4 Peripheral input selection

PeripheralCCP3  CON $0B                     '    Datasheet table 13-3
PeripheralCCP4  CON $0C
RD2PPS = PeripheralCCP3                     ' Pin D2 output source selection
RD3PPS = PeripheralCCP4                     ' Pin D3 output source selection
RB0PPS = 0                                  ' Disable CCP3 (moved to D2)
RB5PPS = 0                                  ' Disable CCP4 (moved to D3)

ANSELA = %00000000                          ' No analog operations
ANSELB = %00000000
ANSELC = %00000000
ANSELD = %00000000
ANSELE = %00000000

TRISA = %00000000
TRISB = %00000100                           ' Only pin B2 is Input
TRISC = %00000000
TRISD = %00000000
TRISE = %00000000

IOC_NAV2_Swap_flag      var IOCBF.2         ' IOC flag on pin B2 change

NAV2_Swap_ON            VAR BYTE

NAV2_MHz_Standby        VAr BYTE
NAV2_MHz_Active         VAr BYTE

SwapFrequency           var WORD            ' Temporary variable used for Swapping frequencies

    Pause 500                               ' Let PIC and LCD stabilize

    NAV2_MHz_Standby = 111 : NAV2_MHz_Active = 222
        
    HPWM 3,250,1953                         ' Contrast
    HPWM 4,150,1953                         ' Backlight

    IOCBF = %00000000                       ' Clear all interrupt flags
    
    NAV2_Swap_ON = 0                        ' Clear Swap button is waiting for processing
            
    goto Start

;--- Subroutines ---------------------------------------------------------------

IOCinterrupts:


    if IOC_NAV2_Swap_flag = 1 then          ' Swap frequencies
        NAV2_Swap_ON = 1
        IOC_NAV2_Swap_flag = 0
    endif
@ INT_RETURN

Start:
    LCDOUT $FE, 1 : Pauseus 1
    LCDOUT $FE, $80, "COM/NAV ENCODER TEST" : Pauseus 1
        
@ INT_ENABLE IOC_INT
    PAUSE 500

Mainloop:
    if NAV2_Swap_ON = 1 then                ' Swap button has been pressed
        SwapFrequency = NAV2_MHz_Standby    ' Swap MHz frequency
        NAV2_MHz_Standby = NAV2_MHz_Active
        NAV2_MHz_Active = SwapFrequency

        NAV2_Swap_ON = 0                    ' Turn OFF swap flag
    endif
 
    LCDOUT $FE, $D4, "NAV2:", dec3 NAV2_MHz_Standby,_
                         "  ", dec3 NAV2_MHz_Active : Pauseus 1

    goto mainloop
end

Gutted code and left only LCD for my observations.