Topaz seems to continually write busted DNG files.
We have seen this problem before: DenoiseAI + Darktable incompatibility and darktable : Opening a dng file from PL5
It is excellent that RawTherapee has done the work to be able to read them, there just doesn’t seem to be that want or drive from the darktable side.
Perhaps you can raise the issue with Topaz, as they presumably have paid staff who might be interested in producing files of better quality.