I too am using privacy badger and yes, disabling it fixed the issue. I didn’t occur to me that this could be the reason. I tend to guess that netlify’s target group is above average tech savvy which could mean above average usage of privacy tools. I also use gasmask e.g. so maybe it could make sense to add some info on the error page that the user should disable its ad / dns blocker. Either way, happy to be able to use the new feature now! Thank you @jen and @midzer!