ICM-42688-P FIFO

We have struggles understanding the FIFO of ICM-42688-P. Currently we do the following:

Setup:
1) Enable INT1 to use FIFO threshold
2) Set FIFO threshold
3) Enable FIFO for Gyro and Accel
4) Enable Gyro and Accel

Loop:
If INT1 happened:
1) Read FIFO count
2) Read FIFO count amount of bytes from FIFO_DATA.

The interrupt fires only once. After investigation we discovered that the FIFO count is not reset after reading the FIFO_DATA register. We also tried FIFO_FLUSH after FIFO read but FIFO count is never resets.
What is the correct way of reading the FIFO?