Hello,
I was able to find the issue using an oscilloscope. I found out that there were some small spikes in the clock signal generated by the FT232H device. As a result the slave interpreted it as a clock pulse and sent the next byte. So at the end, by default the data line was set to high asuming the communication is completed so the date read by LabVIEW was always 'FF' after 1 or 2 bytes.
In order to fix this problem, I added a small capacitor (680pf) between clock line and the ground.
This solved the problem and I am able to now receive the expected output. 😊
