Usage of an USB2AX with XL-320 (Dynamixel v2 protocol)

So the issue is present even if you control only one motor (with sync_read) ?
200Hz is very high for a sync_read packet (200*23 packets/s )
It shoudn’t impact the USB2AX, but on Windows, you have to change the latency of the FTDI driver (16ms by default) to 0 (or 0.1ms) for the USB2Dynamixel.