Question: Can't upload custom tones to iPhone 8
I lost all of the custom ringtones I made previously, and had used for ages on my previous iPhones. Today I finally resolved the issue by re-importing the ringtones into garage band and then exporting to iTunes - from there I dragged the new tone from the iTunes Media - Import folder back into the Tones folder on my phone. If you need help with garage band this site was really useful.
I hope this helps.
And phewy to apple for making this an issue.