Subdomain to Subdomain Calls are getting blocked recently



I have been using some script which is on a subdomain and calling it from different subdomain of same domain the requests are getting blocked for no reason since last 1 day previous there is no issue. I checked disabling DNS and proxy of cloudflare then it started working fine whenever i enable that all my calls to subdomain are giving weird response. Please help on this the same thing work perfectly since 1 years from past 12-24 hours this is happening.