I found out the problem..
It is the SN65HVD234D ! Just not working! I changed to the SN65 because it had some better values like more bandwith, lower power (not that this is prio) and it didn't needed 5V.
The SN65 worked perfectly all in lab, all devices could communicate and everything looked fine. It is a bt more expensive the SN65.
Now I have 16SN65 laying around here without any use.. What do you think what can be the reason, any idea?
The MCP2562 worked now immediately. Again thrown 2 days..