I did this. Left the car to sleep for almost 3days ... but still no luckHello,
I had the same issue and I solved it. But I am not sure if this is the right way to solve it.
First, I open port 0x03 with tools32 and didn't initialize the flexray. I left my car like that for a long time. I don't know if the car update parameters after a period of time. Also I retrofitted 5AD and 5DP and the port 0x03 is still open and I can know initialize Flexray without any problems on port 0x03. See the picture.