Sounds to me like you're answering your own question.
The Naive Instruments website lists two versions of the Komplete Audio 6 interface; the MK1 and the MK2.
If you have the MK1 then I'm inclined to agree that it may not be compatible with macOS Tahoe and maybe it's time to find an interface that is. That might be the MK2.
If you have the MK2 version, then I would first make sure that I've installed the latest firmware update for that model. It's available at the link I posted above. If it has the latest firmware on board and you still have problems after contacting Native Instruments for guidance, then yes, it's probably time to look for a different interface.
Native Instruments is who you should be asking about compatibility of their interface.