On AM64x, the following combination causes no issues:

clock frequency = 192 MHz

baud rate = 1333333

operational mode = 16x 

AM64x SysConfig diagram:

On AM62x, the same exact combination causes SysConfig to throw exceptions.

AM62x SysConfig diagram:

Probable Fix/Solution:

Let us align with same conditions on both AM64x and AM62x UART SysConfig configurations. Customer has successfully been able to run clock freq = 192 MHz, operational mode = 16x and baud rate = 1333333 on Linux. So it should be fine for RTOS as well.