We are using two SC16is752 to communicate with four different UART devices. But when enabling the sleep feature in the IC's the initial received bytes from the external devices are always lost. Depending on baudrate different amount of data is lost.
I have verified the setup of the SC16is752 many times and cannot see what I can do wrong to get this issue. I cannot find any documentation regarding it or any other reported issues either.
My solution for the problem so far has been to trigger the CTS input pin of the SC16is752 a few milliseconds before sending data to it. But I cannot do this for all external devices since I am not in control of them plus some are not using RTS/CTS.
I need help to understand what I might have done wrong in our HW design or the configuration.