Problem with I2C master on ICM20649

Hi everybody,
I am using ICM20649 on SPI and MAG3110, which is connected on Auxiliary master I2C bus of ICM20649.
Communication with ICM20649 on SPI is working.
At first I can communicate with magnetometer too, for example, I can read WHO AM I register.
This problem occurs shortly after configuring:
1) communication with magnetometer is stopped (no activity more on auxiliary i2c master)
2) write to many registers of ICM20649 is ignored (for example USER_CTRL, I2C_MST_CTRL, I2C_SLV0_CTRL ....). I cannot change context of many registers, they contains the previously written value.

Helps only the device reset (writting 0x80 into PWR_MGMT_1) but after few seconds the situation is repeated. I cannot use the magnetometer really.

The ICM20649 configuration is here:
{ICM20649REGISTER::ICM20649REG_BANK0_PWR_MGMT_1, 0b00000001}, //sleep disable, lp disable, temperature enable, clksel=1
{ICM20649REGISTER::ICM20649REG_BANK0_USER_CTRL, 0b00110010}, //DMP disable, FIFO disable, I2cMaster enable, i2c disable, i2c master reset
{ICM20649REGISTER::ICM20649REG_BANK0_INT_PIN_CFG, 0b10010000}, //INT active low, push-pull, pulse, anyclear, fsync int disabled
{ICM20649REGISTER::ICM20649REG_BANK0_INT_ENABLE_1, 1}, //enable raw read int
{ICM20649REGISTER::ICM20649REG_BANK2_GYRO_SMPLRT_DIV, 0x00}, //GYRO_SMPLRT_DIV=0
{ICM20649REGISTER::ICM20649REG_BANK2_GYRO_CONFIG_1, 0b00100111}, //GYRO_DLPFCFG=4(BW 23.9Hz), SCALE=+-4000dps, GYRO_FCHOICE=1
{ICM20649REGISTER::ICM20649REG_BANK2_ACCEL_CONFIG, 0b00100111}, //ACCEL_DLPFCFG=4(BW 23.9Hz), SCALE=+-30G, ACCEL_FCHOICE=1
{ICM20649REGISTER::ICM20649REG_BANK2_TEMP_CONFIG, 6}, //TEMP_DLPFCFG=6(8.8 Hz)
{ICM20649REGISTER::ICM20649REG_BANK3_I2C_MST_CTRL, 7}, //Page81: To achieve a targeted clock frequency of 400 kHz, MAX, it is recommended to set I2C_MST_CLK = 7 (345.6 kHz / 46.67% duty cycle).
for configuring/checking of magnetometer I am using SLV4: for example read WHO AM I:
ICM20649REG_BANK3_I2C_SLV4_ADDR <--- 0x8E);
ICM20649REG_BANK3_I2C_SLV4_REG <--- 0x07);
ICM20649REG_BANK3_I2C_SLV4_CTRL, 0b10000001); //start, len=1 B
wait some ms
result is in ICM20649REG_BANK3_I2C_SLV4_DI -> 0xC4
for reading of data I am using SLV0
ICM20649REG_BANK3_I2C_SLV0_ADDR <--- 0x8E);
ICM20649REG_BANK3_I2C_SLV0_REG <--- 0x00);
ICM20649REG_BANK3_I2C_SLV0_CTRL, 0b10001000); //start, len=8 B

Does anyone have any idea how to solve this problem?
Or am I doing something wrong?

Thanks,
J.Kovacs