I recently migrated a website from one server to another, and the worst thing ever happened. Every single URL on the site jumbled together because in the settings I did not have the forward slash mark at the end of the URL.
So links that would normally be https://ChristmasWebmaster.com/directory, for example, were formatted https://ChristmasWebmaster.comdirectory. Obviously, that is going to make your links not work properly.
Since it was a very large site and this happened to every single URL in the site I had to go back by hand and change every single product category link, every single menu item, etc., and it took hours. So before you begin a migration make sure you go to settings and check that the URL has the slash mark at the end of it!