Moving to a new server into a subfolder

Hello There,

I tried installing a wp-site that I made in one server to another one to the same subfolder. But it gives me an error when I change the site url. Just to make the point clear. Here is what I did.

• I copied all the wp folder in my previous server (jacobkolady/rockwell2) and pasted it in bluehost server (rockwellqatar/rockwell2)
• Then I copied the db and ran a find and replace action to replace jacobkolady.com to rockwellqatar.com. As the folder structure was same (rockwell2) it neednt be changed.
• I go to the link https://www.rockwellqatar.com/rockwell2 everything works perfectly at it did in my old server.
• Then I go to the general settings —>site URL and change the site url to https://www.rockwellqatar.com.
• Then when I visited the site it starts giving me error. This is where Iam at. And so I changed the site url back to how it was and its working normal now except its still https://www.rockwellqatar.com/rockwell2.

Im very sorry if I have done something seriously stupid. Any help would be deeply appreciated as Im quiet new to this moving stuffs!

Also i tried the solution of copying the index and htaccess file to the root folder and change the index file to the respective url. Still it dint give me a solution.