SSL is full.
I changed Nameservers on 5/25.
This problem has lasted about 5 hours.
First appearance:
502 bad gateway error
After I asked Siteground to say that it is a DNS issue, later appearance:
Siteground (your hosting) returns a 404 error for https://aiirly.com/.
Can you share a screenshot of your NS settings in Cloudflare account (redact IPs)?
If you try to use Cloudflare directly the problem is your hosting changes your IP frequently and as you see in automatic records generated by CF, they are wrong (they were correct at the time CF gathered them but changed later).
Fixed IP is not mandatory. You can use CF with your current hosting provider, I just explained what is going on. Follow the tutorials and it will work.