What exactly is the problem? In a unit grouping or in an assembly diagram? This diagram is described in some detail both visually and in the plan of the table, which indicates the steps for the assembly, which, for example, can be skipped and done later, because some modules were later transferred.
I'm not sure but you probably need to update Community Resource Pack. In HabTech archive this mod have 1.0 version, on githab of this mod - 1.4.2. I'm troubleshooting same bug right now, will answer if updating of this mod helps. UPD. Nah, it didn't work. Maybe there is some mod whuch breaking this exact truss, dunno. https://imgur.com/a/XE4YbSx UPD2. Found a reason after disabling mods 1 by 1. In my case it was Parallax. Bye-bye parallax, ISS right now is more important for me.