For the SSL certificate, I use cerbot because --letsencrypt --force doesn't work for me.
I have Cloudflare DNS only.
On another website for my friend working flawless,
What can I do? I have a backup for WordPress. Delete the website and start from the beginning?
And if SSL doesn't work again?
Now can I add HTTP/2 and how?
Which is the best solution?
Finally, just add listen 443 ssl http2; Done!