Solution at the end of the thread - using the web interface to delete the erroneous Custom DNS entry.
I just deleted all of these DNS entries, and all, EXCEPT ONE, gave me that same internal 500 server error. Status page right now gives me a bunch of red errors for that domain, while I’m waiting for the usual propagation delays to resolve.
I think this might fix this issue (), but this also indicates that there is a pretty serious bug underlying this (going back to at least 2015).
), but this also indicates that there is a pretty serious bug underlying this (going back to at least 2015).