Hello Becky,
Thanks for reaching out! I’m really sorry about this 502 issue. Let’s try to fix that.
The “502 Bad Gateway error” usually means that the server was acting as a gateway or proxy and received an invalid response from the upstream server. This usually has something to do with the server where your website is located, or another server used at your hosting provider where the data goes through.
Try to test deleting some regular posts or pages. Do you get the same?
Can you send me a screenshot of the error?
This article contains a thorough explanation on what this is and also has a section on what you can do to fix it.
I hope this will help. Let me know how far you get.
Cheers,
Andras