Error: Invalid Swift Support when uploading a build to iTunes Connect

Have you seen this?

https://developer.apple.com/library/content/technotes/tn2435/_index.html#//apple_ref/doc/uid/DTS40017543-CH1-TROUBLESHOOTING

Search for "Embedded .dylib Files"

I would try to follow that steps, It should work.

Make sure you have the 'Always Embed Swift Standard Libraries' at its default setting in your main target and possible other targets (extensions). Also make sure you don't archive Release version with a Debug setting (Scheme).

The solution here was to add a new target to my project, the first Framework option that Apple gives and to move the .dylib file and the interface.h file into it. Link the interface.h file into my framework.h file, import the framework into my main target

Happy to give more info (it's a longer answer) if anyone needs it. Just leave a comment.