Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32U599/OTG_HS/GRXFSIZ#0x0
The application can program the RAM size that must be allocated to the Rx FIFO.
RXFD
https://github.com/cmsis-svd/cmsis-svd-data