Yes, I tested this update today and it seems that it solved the problem.
Thank you very much.

Hi llewellyn,

Did you solve UART issue?
Thanks in advance.

Thank you WiFive.
I applied this fix but it continues with the same problem.

I have the same problem with a UART.
After the buffer full up, all data is wrong, with or without a flush.
If I change the program to never leave the buffer full, everything works perfectly.
Did you find a solution about?