Send Cut Send STEP Files

I’m trying to work with the company “Send Cut Send” to get some prototype parts made (both sheet metal and machined). Normally STEP files can be uploaded to their site and quotes will be generated automatically with their software. For some reason CREO STEP files do not work. I reached out to their customer service and they are telling me...

“CREO is not recommended at all towards our production processes due to how they configure their exports. We generally recommend exporting 2D vector files from software to eliminate STEP file upload issues. However, when using Creo, that process is not straightforward. I recommend checking out our preferred software (https://sendcutsend.com/blog/recommended-software/) or looking for export guidance through their direct forums. 
 We highly suggest using software like Fusion 360 (https://sendcutsend.com/blog/how-to-export-a-dxf-in-fusion-360/), AutoCAD, or SolidWorks (https://sendcutsend.com/blog/exporting-to-dxf-from-solidworks/).”

This is interesting because companies like Xometry have zero issues with CREO STEP files. CREO is my only option for these parts.

I’ve tried several different save options when creating CREO STEP files (using options > “STEP Export Profile Settings”). Nothing seems to work. The test is to try uploading the files to their site, but I always get the spinning wheel of death. They do have a video that talks about creating 2D DXF files using CREO, but this is not ideal for what I’m trying to do. Also, they do not seem interesting in fixing the problem.

Any suggestions?