Resolved! Error in STM32G4 reference manual RM0440, revision 7 (February 2022), section 44.3.3 Message RAM of FDCAN peripheral
Figure 669. Message RAM configuration clearly shows that the message RAM is 0x350 bytes long which corresponds to 212 32-bit words. But later the following example is used to show, how the message RAM of FDCAN2 follows message RAM for FDCAN1:As an ex...