A person decided to migrate their site from one server to another. They also changed hosts at this time. The person forgot to include the "www" in their site's address. This person has already noticed that their error negatively affected their SEO, and this has only been in place for a short period of time. The person wanted to know if it is possible to fix the error in the settings section of their new server or what else they might be able to do in order to solve this problem. The person noted that they can add additional domains in the setting.
One person wrote back with a suggestion to set up a redirect to the correct URL. They said that it should not matter which one is in the server and which one is in the redirect option. Another person wrote back with more details that it should not make a big difference about which one is in the apex domain and which one is in the subdomain for servers. They noted that the major concerns are choosing one or the other, but not both. The choice has to be consistent throughout all of the server's settings. The server should not be serving off of both of the domains for the site. This person also recommended checking what is on Google Search Console and making sure that it is correct, given the recent SEO drop.
Fixing the issue in domain management should not take much time or effort. However, the statement of the original poster that their SEO dropped at the same time is more concerning. This should not have happened unless something else got mangled in the migration of one server to the other. Everyone suggests that the person delete the site.com URL and replace it with www.site.com as the URL. The poster needs to follow through by checking everything else with Google where there may be a URL error since the migration took place. The Google Search Console has a preferences section where the site owner can check the preferences for the site's preferred domain property. For more information click here https://www.reddit.com/r/SEO/comments/blbyuu/mademistakewhenmigratehosting_server/.