Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32F469/OTG_FS_GLOBAL/FS_DIEPTXF5#0x0
OTG_FS device IN endpoint transmit FIFO size register (OTG_FS_DIEPTXF5)
https://github.com/cmsis-svd/cmsis-svd-data