Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32n6/STM32N645/OTG1/OTG_HCTSIZ6#0x0
DPID=B_0x0
OTG host channel 6 transfer size register
Transfer size
Packet count
Data PID
0 (B_0x0): DATA0
1 (B_0x1): DATA2
2 (B_0x2): DATA1
3 (B_0x3): SETUP (control) / MDATA (non-control)
Do Ping
https://github.com/modm-io/cmsis-svd-stm32