Ok. That's "good" news in my eyes. That means this definitely isn't related to VISA cards and seems to be different depending on which bank the card is from. Just strange that ING DiBa is showing this behaviour...
I'm not familiar with the exact process behind adding the cards and what steps are followed, but I assume Apple's servers first check the BIN with a simple binary "allowed / not allowed" and then collect the data they need from the banks to authorise adding the card - including generating the device account number for tokenisation. That's where this second step must kick in. From what I can see it tries to add the card but fails then. That's one step further than a locked BIN number (such as with Revolut). Interesting...
Would be happy to hear what you are all seeing. It would also be helpful to state with which cards you have tested it with. Amex would also be interesting but don't have a German issued one to test.