Custom page for WAF Block, get the 500

Hi, to follow up the issue, and give some feedbacks :

I found something interesting !
The HTTP status returned by the blocked page is 403, BUT… the page used the one for 1000x errors, and indeed, the code is 1020 !
I didn’t know that a blocked page obtains a 1020 (https://support.cloudflare.com/hc/en-us/articles/360029779472-Troubleshooting-Cloudflare-1XXX-errors#error1020)

If I understand, the 1020 code has nothing to do with the HTTP status, it’s an error code, not an HTTP code, isn’t it ?