I am getting this error 520 for at least one week and it is inconsistent, Most of the time it is not working but sometime the error goes away, I have spoken to my host provider globat and they can’t help on this. Unfortunately this seems to be a Cloudflare issue that needs to be sorted out sooner than later otherwise people using this service will leave.
Sorry I don’t have any idea on what needs to be done to fix this issue. Whether it is a paid service or not, the issue seems to be the same.
I’m sorry, but as far as I’m aware, it’s not possible. There’s the “Custom Page” section to handle certain status codes, but nothing for the 1xx ones. It may be possible to do something with Workers, but I’m not sure.
Is it just the origin server that needs to return 100, or do you need to return it all the way through to the client?