@rubenkamlah
Hey I got the same problem as you : when I am re-amping my DI track back into the Helix, I am losing a lot of gain (or volume I don't know, but I'm clearly losing something, like a signal loss somewhere).
I will try your method : record my DI on a stereo track with USB 7 and 8, and setting the output of that stereo DI track also on USB 7 and 8 for re-amping back into the Helix (if I get whet you said correctly, not very good in english here, and still a beginner in recording guitars so...)
If you have made a youtube video about this problem since 2020, let me know i'm interested.
Cheers.