Homepage 404 after changing siteurl

I just built my first site using wordpress.

I built it at https://www.synoiatech.com/wordpress

When I was ready to launch the site I followed the instructions here https://codex.www.ads-software.com/Giving_WordPress_Its_Own_Directory > ” Using a pre-existing subdirectory install” to move it to the root directory.
After I moved the site all of the pages work with the exception of the home page. On the HP I see the menus and logo but i get a 404 where the main content should be. Also all of the pages show the new permalink ex: https://synoiatech.com/about-us/ except for the hp which loads as https://synoiatech.com/wordpress/.

If I try to make any other page the front page using settings > reading, that page stops working and gives the 404. As a result I have created a “Home” link in the main navigation just so I could see what my HP looks like.

I have been tearing through forums all day looking for possible solutions to the problem and I am under a really tight deadline to launch this site. Any help will be greatly appreciated.

Thank you
Shimon