Gumroad Account Link - Fails with no feedback

In https://jinxxy.com/my/settings, attempting to link my my Gumroad account silently fails. It redirects back to https://jinxxy.com/my/settings?gumroad_error=EXCHANGE_FAILED but no error details are displayed, and it still displays “No Gumroad accounts linked” in the settings.

I’ve tried in both Firefox and Chrome with no adblocker and the results are the same.