Hello Mark,
- "the SYNCH bit in ESR1 of the Flexcan module is set", this meaning FlexCAN is synchronized to the CAN bus.

- And
, could you please tell me which DOC ?
And also do you meaning when you test the example you mentioned , it can not work well ? If yes,
please tell me which , i can check on my side .
You can also describe your problem in detail .
Hope it helps
Alice