For what it’s worth, I’ve had this behavior as well. I’m using a Babyface pro, with the latest RME drivers on the latest version of wavelab elements. This issue is also present with the previous driver & wavelab version.
I somehow managed to get Asio4All loaded up & that’s been working, but it’s not ideal because sometimes I go back & forth between wavelab & cubase & the driver switching is troublesome. No issues with cubase pro, BTW.
In any event, I’ll try the regedit. Cheers