A section of my Users in Nigeria experiencing "Error 523"

Somehow, some of the users of my website in Nigeria get “Error 523” while every other location works well. I have followed all the instructions that I can find on Cloudflare. There is no problem at all with my Host. I know this because other websites that I have not passing through Cloudflare works well in all locations.

When I disconnect CloudFlare, the website works well for everybody, but when I connect Cloudflare, some users still receiving Error 523.

Any help will be highly appreciated. My website is https://dottedjewelry.com

Thanks.