I've been using a password manager for years to login into the game (currently using KeePassXC) and its auto-type feature stopped working in royals client after the update. It correctly alt-tabs into the client but is unable to type my credentials into the login/password fields. Probably related to the "additional anticheat measures" that were added. Please fix this, it's a bit ridicoulus that such basic feature as logging into the game gets broken
It’s probably related to admin privileges being required to interact with the client. Try launching your password manager as administrator and see if it works, or follow Yeepogs instructions here: