The chips have arrived. I tried RAB change interrupt on a demo board. The situation is the same with isis. This is my test code below.

Code:
    INCLUDE "DT_INTS-18.bas"     ' Base Interrupt System
    INCLUDE "ReEnterPBP-18.bas"     ' Include if using PBP interrupts
    
    ........

    OSCCON  = %00110100
    OSCCON2 = 0
    OSCTUNE = %10000000
    
    TRISA   = %11101111
    TRISB   = %11111111
    TRISC   = %00000000

    ANSEL   = 0
    ANSELH  = 0
    
    INTCON2.7   = 0
    WPUA        = %00101111
    WPUB        = %11110000
    IOCA        = %00000111
    IOCB        = %01010000

    ASM
INT_LIST  macro    ; IntSource,      Label,  Type, ResetFlag?
                    INT_Handler   RABC_INT,  _RABC,   PBP,  yes
    endm
    INT_CREATE               ; Creates the interrupt processor
    INT_ENABLE  RABC_INT
    ENDASM

    MAIN:

   
    ......
GOTO MAIN


     RABC : 
    
    COUNTER = COUNTER + 1
    
    
@ INT_RETURN