Some query show CORS error

I created a site that look like the poocoin site

My site: coinomic

but the problem is when I change the base currency address, sometimes it working fine, and sometimes it shows a CROS error.

Example (working):

Example (not working):

you can try.

The ones that don’t work on my site same addresses that work on poocoin site.

Can anyone tell me the reason for this?