Googlebot blocked by Server Error (5xx) - Site accessible via browser

I think the backslashes are caused by invalid Markdown syntax. Block quotes are used to create links in Markdown, but you’re putting other text in it too. I think that’s confusing the text processing. You should be able to post your URL if you either leave out the block quotes or use the correct Markdown syntax for links.

As for the issue itself, a 5xx error usually means the website is not working correctly or it’s down. If Google was deliberately blocked, you’d see a 403 error, not a 5xx error.

I had a quick look at your site to see if I could find any code that was causing it. No obvious explanations jumped out at me, but I noticed that you do have both a WordPress installation and static HTML content. If you switched from WordPress to static HTML, I would recommend to delete the WordPress installation from your website to avoid any conflicts.