I noticed you have several good questions on the forum.
I was wondering if you too have experienced erroneous CYBLE-022001 UART transfers.
For example, when the UART function SCB_1_UartPutString("Test\r\n"); is called periodically (e.g. every 50 milliseconds), the data transferred from the UART is often erroneous with only a few characters (e.g. Te) transferred. Depending on how often the data is transferred, the UART will often only set the Tx line low for about 500 microseconds and then back high. The UART settings are: Mode=Standard, Direction=TX+RX, Baud rate=115200 (actual 115385), Data bits=8, Parity=None, Stop bits=1, Oversampling=16.
Thank you for your time and the excellent questions you have posted,
Really wish I could help but I haven't played with the UART functions on these chips.
That said, the first thing I would do is confirm your findings with a logic analyzer and/or scope analysis of your data stream.