Let's say I have a website example.com which is an original one. I have other 4 sites like example1.com - example2.com - example3.com & example4.com All the domains are pointed to the same server. I had installed a canonical tag of example.com in all other domains.
Last week I had a sudden ranking drop for 120 keywords. I found out that my other domains with more DA are competing with each other.
We can't use noindex or 301 redirects for other domains. Is there any way to solve this issue?
Any suggestion would be appreciated..