When investigating pages the site might appear to be bringing users to templates that are not configured within the folder or template automatic aliasing rules. Further when entering a redirect the page may still bring users to an unexpected page.
Regex aliasing is a method for predicatively creating aliases for items. If a URL redirect entered through the workarea matches a regex expression the redirect would not take place.
Regex aliasing is a method of automatic aliasing that predicts a pattern of an alias and automatically redirects users to a relevant page. Since regex aliasing requires the development of a regex expression this type of aliasing can often be overlooked when troubleshooting.
To disable a regex aliasing navigate to settings > configuration > URL aliasing > automatic aliasing > regex. Then click edit list, uncheck the active checkbox, and click save list.