For anyone else having this issue, there is a way to manually add the mods to your manifest file. While this is not a fix and is highly annoying to have to do this for dozens of mods, it will allow your modpack to be uploaded to curseforge. You can go to the mod's page and find the projectID on the right-hand side of the page. Then the fileID can be found by going to files section of the mod and clicking the version you want to include in your pack. The last 7 digits of that URL are the fileID. Hope this helps some people while we wait for a fix for the export function.