Yeah it's going to take a while for RL to fix this for CC4. I'm having issues with it too.
You're better off importing (transforming) on CC3 for now and then open your project file on CC4.

I was getting this problem too
I noticed it was happening when I was trying to use 4k textures

Using Transformer in Advanced mode in CC4 to bake textures gives a weird result. I tried a couple of times with different DAZ characters always with bad results.
76% of original size (was 658x19) - Click to enlarge

The same FBX file with the same Texture INI profile in CC3 gives the correct result
76% of original size (was 658x19) - Click to enlarge

I hope this can be fixed soon.