Alias domain getting redirected to main domain

Hi I’m having problem with my alias domains.

I made a website in paste.mydomain.com alias domain
But the website is being redirected to main domain mydomain.com

Few days ago I created a website drive.mydomain.com .It’s working fine till now. But since yesterday when I create any new alias domain it gets redirected to main domain.

I tried to create page rule & 301 redirect but it gives error in chrome saying too many redirects.

I’ve mailed support but no reply.

Please help me to fix the issue

No offence, but the information you posted is somewhat useless.

Post the actual domain, all DNS records in question, and screenshots of your page rules.