diff --git a/apps/dav/lib/Connector/Sabre/Auth.php b/apps/dav/lib/Connector/Sabre/Auth.php
index 7b959a0d89..27900cc1ca 100644
--- a/apps/dav/lib/Connector/Sabre/Auth.php
+++ b/apps/dav/lib/Connector/Sabre/Auth.php
@@ -110,10 +110,10 @@ class Auth extends AbstractBasic {
 			$this->session->close();
 			return true;
 		} else {
-			\OC_Util::setUpFS(); //login hooks may need early access to the filesystem
+			\OC_Util::setupFS(); //login hooks may need early access to the filesystem
 			if($this->userSession->logClientIn($username, $password)) {
 				$this->userSession->createSessionToken($this->request, $this->userSession->getUser()->getUID(), $username, $password);
-				\OC_Util::setUpFS($this->userSession->getUser()->getUID());
+				\OC_Util::setupFS($this->userSession->getUser()->getUID());
 				$this->session->set(self::DAV_AUTHENTICATED, $this->userSession->getUser()->getUID());
 				$this->session->close();
 				return true;
diff --git a/lib/private/User/Session.php b/lib/private/User/Session.php
index e1ede95e2a..f560bb4bfc 100644
--- a/lib/private/User/Session.php
+++ b/lib/private/User/Session.php
@@ -361,7 +361,14 @@ class Session implements IUserSession, Emitter {
 			// TODO: throw LoginException instead (https://github.com/owncloud/core/pull/24616)
 			return false;
 		}
-		return $this->login($user, $password);
+		if (!$this->login($user, $password) ) {
+			$users = $this->manager->getByEmail($user);
+			if (count($users) === 1) {
+				return $this->login($users[0]->getUID(), $password);
+			}
+			return false;
+		}
+		return true;
 	}
 
 	private function isTokenAuthEnforced() {
@@ -376,7 +383,11 @@ class Session implements IUserSession, Emitter {
 		);
 		$user = $this->manager->get($username);
 		if (is_null($user)) {
-			return true;
+			$users = $this->manager->getByEmail($username);
+			if (count($users) !== 1) {
+				return true;
+			}
+			$user = $users[0];
 		}
 		// DI not possible due to cyclic dependencies :'-/
 		return OC::$server->getTwoFactorAuthManager()->isTwoFactorAuthenticated($user);
@@ -385,7 +396,7 @@ class Session implements IUserSession, Emitter {
 	/**
 	 * Check if the given 'password' is actually a device token
 	 *
-	 * @param type $password
+	 * @param string $password
 	 * @return boolean
 	 */
 	public function isTokenPassword($password) {
diff --git a/lib/private/legacy/api.php b/lib/private/legacy/api.php
index 1e581153ce..024f3c0fb6 100644
--- a/lib/private/legacy/api.php
+++ b/lib/private/legacy/api.php
@@ -349,7 +349,7 @@ class OC_API {
 			if ($ocsApiRequest) {
 
 				// initialize the user's filesystem
-				\OC_Util::setUpFS(\OC_User::getUser());
+				\OC_Util::setupFS(\OC_User::getUser());
 				self::$isLoggedIn = true;
 
 				return OC_User::getUser();
@@ -374,7 +374,7 @@ class OC_API {
 			self::$logoutRequired = true;
 
 			// initialize the user's filesystem
-			\OC_Util::setUpFS(\OC_User::getUser());
+			\OC_Util::setupFS(\OC_User::getUser());
 			self::$isLoggedIn = true;
 
 			return \OC_User::getUser();