I'm pretty sure I've found a fix. I ran into this problem when installing a theme on Windows 10 and it hasn't happened since using this. https://mega.nz/#!5ptE0CxB!tAdYmz9b6478yrvr6DPfzKOeP0xThdG-bxs8jLcG79M Here's the download link. It's a .cmd file, and running it disabled the new search in Windows 10. There's also an included option to get it back. (Why would you want to though?)
https://virtualcustoms.net/showthread.php/84200-Width-of-address-bar-%281909%29?highlight=1909 Here is the original source. Props to whoever made it from this thread. Again the instructions are: Download the file from the mega link, run the disable new search bat file, and wallah it's done. Run the enable new search to get it back. Let me know if it works for you guys!
^Here is a virus total for the disable new search.cmd file.