Hello. I downloaded dfx file from here https://www.thingiverse.com/thing:612630 and tried to open it in carbide create.
Here is what it looks like when it opened. Looks weird.
Dxf is a horrible format… different programs create different variations of dxf. Some are correct according to the “standard” and some are not. Programs that import dxf have to try to deal with all these crazy variations.
If you send that file to support@carbide3d.com and ask them to look at it - they will likely fix the import problem in the next Carbide Create update.
Meanwhile, using an intermediary program such as Inkscape and then export as an SVG will often work well… but the extra step is a PITA.