I have this exact same problem. My Figma file uses Roboto (free Google font). It claims that 4 custom fonts are missing and they have different font names to the ones I use. Each has 'Roman' added to the name and the font weight names are not the same. I have tried renaming the fonts and uploading but this does not work. Unable to setup the typography section as a result.

Hello Kryston Schwarze,

We'll try to look into it. Can you try to upload one font first, the Regular one by clicking the upload icon next to it. Do you have the same message?

I'll contact you via our Chat so we can investigate further.