Old Siteground home page showing up in Digital Ocean server

I moved my site from SiteGround to Digital Ocean recently. The DNS has propagated successfully (domain.com and staging.domain.com). This has been confirmed by both the domain registrar and digital ocean. But when I go to my live site I still see the home page from Siteground ( I only had one page there as a placeholder). I can see all the other pages of my new site by typing them into the address bar, but not the home page. In trying to troubleshoot the problem, I went to Siteground and deleted everything having to do with this domain. But the Siteground home page is still showing up on the live site. The only explanation is that the page is cached somewhere. I called Siteground and they insist that it is nothing on their end, since the domain has been deleted.

More info that may help - before transferring my domain name servers to Digital Ocean on my domain registrar, I tried to redirect the domains from Siteground to Digital Ocean by creating A records (one for staging.domain.com and one for domain.com) and giving them my new Digital Ocean server’s IP address. It didn’t seem to work, so I went to plan B and changed the name servers on my domain registrar. I suspect Digital Ocean has that old page and is holding on to it, even though I have deleted those A records in Siteground.

One more thing - in my Siteground site in Filezilla I can see a .SGCache directory containing a cache_status file with this line: static||staging.domain.com||1. I tried to delete it but Filezilla says I don’t have permission. There is also a ‘staging’ folder in the public HTML directory that contains a .htaccess file with rewrite conditions for the staging site.

I am a student and this is a project that I need to have done very soon. Prompt assistance would be very much appreciated!