I've got the opposite problem a lot of people can when switching servers. All the pages work fine, EXCEPT the home page, which is generating a 404. It's just the blog URL by itself (mysite.com/blogfolder/). Wordpress is installed in a folder in the site root, and worked fine at the old host. htaccess is all what it is supposed to be for this kind of installation. What could cause this??
If you are using a static page as homepage, make sure that the page which you were using as static homepage actually exists.
Have a look at this. It's fairly the same scenario.
I had the same problem after Ubuntu Upgrade 16.04 to 18.04, and it was solved by pressing "Purge Caches" in /wp-admin/admin.php?page=w3tc_objectcache