PIC I2C clock configuration - c

Question

I am trying to communicate with a device using PIC18F26K83. Max freq for SCL is 1 Mhz according to devices datasheet. When I set I2C clock to HFINTOSC (1 Mhz) it can communicate with a device (As long as my system clock is between 250 Khz and 1 Mhz). I do not change anything I just change system clock from 500 Khz to 1 Mhz and it stops working. How can it be? I use HFINTOSC which is set to 1 Mhz for I2C clock, is that depend on the system clock?
And my other question is again related to I2C clock. Like I said when I use HFINTOSC for I2C clock, it works as long as system clock is 500 kHz. However, When I try to use Fosc or MFINTOSC with (500 kHz or 1 MHz system clock) it does not work. Can anyone guide me in here? Because I am stuck and I do not why how can this happen.
Codes for setting up the internal oscillator:
// OSCCON1 REGISTER
NOSC2_BIT=1;
NOSC1_BIT=1;
NOSC0_BIT=0;//HF INTERNAL OSC
//OSCFRQ REGISTER HFINTOSC FREQ. SELECTION
FRQ3_BIT=0;
FRQ2_BIT=0;
FRQ1_BIT=0;
FRQ0_BIT=0; // 0010 : 4 MHz , 0000:1 MHZ
NDIV3_BIT=0;
NDIV2_BIT=0;
NDIV1_BIT=0;
NDIV0_BIT=1;//DIVIDE BY 2
Codes for I2C configartion:
//MODULE ENABLE
I2C1CON0.B7 = 1;
delay_ms(500);
I2C1CON0.B7 = 1; //MODULE ENABLE
I2C1CON0.B6 = 0; //RSEN=0,RESTART ENABLE
I2C1CON0.B2 = 1;
I2C1CON0.B1 = 0;
I2C1CON0.B0 = 0; //MASTER MODE 7 BIT*/
I2C1CON1 = 0X80;
// SDA SCL pin ayarları
TRISC.RC4 = 0; //I2C:SDA
TRISC.RC3 = 0; //I2C:SCL
LATC.RC4 = 0;
LATC.RC3 = 0;
ANSELC = 0XE7; // Clear RC3,RC4 analog inputs
ODCC4_BIT = 1; //open drain control register, sink current only
ODCC3_BIT = 1;
WPUC4_BIT = 0;
WPUC3_BIT = 0; // WEAK PULL UP DISABLE
//RXYI2C SLEW RATE PULLUP VS
RC3I2C = 0X01;
RC4I2C = 0X01;
SLRCONC.B4 = 0; //NO SLEW RATE LIMITING
SLRCONC.B3 = 0;
//PPS AYARLARI
PPSLOCK = 0X55; //UNLOCK SEQUENCE
PPSLOCK = 0XAA;
PPSLOCKED_BIT = 0;
RC3PPS = 0b00100001; //SCL OUTPUT RC3
I2C1SCLPPS = 0b00010011; //SCL INPUT RC3
RC4PPS = 0b00100010; //SDA OUTPUT RC4
I2C1SDAPPS = 0b00010100; //SDA INPUT RC4
PPSLOCK = 0X55; //LOCK SEQUENCE
PPSLOCK = 0XAA;
PPSLOCKED_BIT = 1;
//
I2C1CON2 = 0X04;
And codes for I2C clock selection:
// I2C CLOCK
I2C1CLK.B3 = 0;
I2C1CLK.B2 = 0;
I2C1CLK.B1 = 0;
I2C1CLK.B0 = 1; //0010 HFINT OSC 0001 FOSC
//I2C FREQUENCY=1000/5=200KHz
//FME=0 MEANS DIVISION=5
This is the image of SCL pin when I use 500 Kbps system clock and HFINTOSC for I2Cx CLK.
I checked what I see with MFINTOSC or Fosc as I2CxCLK and it is empty. 0V. No clock unfortunately.