Hello @AdOtjuh, welcome to the Nextcloud community! 
please open dev tools (F12) and review the destination of redirect. Often it helps to understand to reason of wrong redirect.
IMO this setting is always causing trouble.. try to remove it..
highly recommend to avoid this. It only cause trouble in many situations like different URLs for internal vs external view - see topics tagged local_network . Better use public domain internally as well 101: Split-Brain DNS (split-horizon)