diff --git a/apps/files_sharing/lib/SharedStorage.php b/apps/files_sharing/lib/SharedStorage.php
index 2d2f14fc55423..5aeabf83e0c55 100644
--- a/apps/files_sharing/lib/SharedStorage.php
+++ b/apps/files_sharing/lib/SharedStorage.php
@@ -124,12 +124,19 @@ private function init() {
 		$this->initialized = true;
 		try {
 			Filesystem::initMountPoints($this->superShare->getShareOwner());
-			$sourcePath = $this->ownerView->getPath($this->superShare->getNodeId());
-			list($this->nonMaskedStorage, $this->rootPath) = $this->ownerView->resolvePath($sourcePath);
-			$this->storage = new PermissionsMask([
-				'storage' => $this->nonMaskedStorage,
-				'mask' => $this->superShare->getPermissions()
-			]);
+			$this->rootPath = $this->getSourceRootInfo()->getPath();
+			$mounts = $this->ownerView->getMountByNumericId($this->getSourceRootInfo()->getStorageId());
+			if(!$mounts) {
+				$this->storage = new FailedStorage(['exception' => new \Exception('Mount for source storage not found')]);
+				$this->cache = new FailedCache();
+				$this->rootPath = '';
+			} else {
+				$this->nonMaskedStorage = $mounts[0]->getStorage();
+				$this->storage = new PermissionsMask([
+					'storage' => $this->nonMaskedStorage,
+					'mask' => $this->superShare->getPermissions()
+				]);
+			}
 		} catch (NotFoundException $e) {
 			// original file not accessible or deleted, set FailedStorage
 			$this->storage = new FailedStorage(['exception' => $e]);
diff --git a/lib/private/Files/Mount/Manager.php b/lib/private/Files/Mount/Manager.php
index 1293b8549a5f1..37223c8200f31 100644
--- a/lib/private/Files/Mount/Manager.php
+++ b/lib/private/Files/Mount/Manager.php
@@ -46,13 +46,17 @@ public function __construct() {
 		$this->inPathCache = new CappedMemoryCache();
 	}
 
+	private function invalidateCaches() {
+		$this->pathCache->clear();
+		$this->inPathCache->clear();
+	}
+
 	/**
 	 * @param IMountPoint $mount
 	 */
 	public function addMount(IMountPoint $mount) {
 		$this->mounts[$mount->getMountPoint()] = $mount;
-		$this->pathCache->clear();
-		$this->inPathCache->clear();
+		$this->invalidateCaches();
 	}
 
 	/**
@@ -64,8 +68,7 @@ public function removeMount(string $mountPoint) {
 			$mountPoint .= '/';
 		}
 		unset($this->mounts[$mountPoint]);
-		$this->pathCache->clear();
-		$this->inPathCache->clear();
+		$this->invalidateCaches();
 	}
 
 	/**
@@ -75,8 +78,7 @@ public function removeMount(string $mountPoint) {
 	public function moveMount(string $mountPoint, string $target) {
 		$this->mounts[$target] = $this->mounts[$mountPoint];
 		unset($this->mounts[$mountPoint]);
-		$this->pathCache->clear();
-		$this->inPathCache->clear();
+		$this->invalidateCaches();
 	}
 
 	/**
@@ -141,8 +143,7 @@ public function findIn(string $path): array {
 
 	public function clear() {
 		$this->mounts = [];
-		$this->pathCache->clear();
-		$this->inPathCache->clear();
+		$this->invalidateCaches();
 	}
 
 	/**
@@ -156,13 +157,10 @@ public function findByStorageId(string $id): array {
 		if (\strlen($id) > 64) {
 			$id = md5($id);
 		}
-		$result = [];
-		foreach ($this->mounts as $mount) {
-			if ($mount->getStorageId() === $id) {
-				$result[] = $mount;
-			}
-		}
-		return $result;
+		$mounts = array_filter($this->mounts, function(IMountPoint $mountPoint) use ($id) {
+			return $mountPoint->getStorageId() === $id;
+		});
+		return array_values($mounts);
 	}
 
 	/**
@@ -179,8 +177,11 @@ public function getAll(): array {
 	 * @return MountPoint[]
 	 */
 	public function findByNumericId(int $id): array {
-		$storageId = \OC\Files\Cache\Storage::getStorageId($id);
-		return $this->findByStorageId($storageId);
+		\OC_Util::setupFS();
+		$mounts = array_filter($this->mounts, function(IMountPoint $mountPoint) use ($id) {
+			return $mountPoint->getNumericStorageId() === $id;
+		});
+		return array_values($mounts);
 	}
 
 	/**
diff --git a/lib/private/Files/View.php b/lib/private/Files/View.php
index 19e3871780344..4789a767346f5 100644
--- a/lib/private/Files/View.php
+++ b/lib/private/Files/View.php
@@ -213,6 +213,17 @@ public function getMount($path) {
 		return Filesystem::getMountManager()->find($this->getAbsolutePath($path));
 	}
 
+	/**
+	 * @param int $id
+	 * @return IMountPoint[]
+	 */
+	public function getMountByNumericId($id) {
+		$mounts = Filesystem::getMountByNumericId($id);
+		return array_values(array_filter($mounts, function(IMountPoint $mountPoint) {
+			return $this->getRelativePath($mountPoint->getMountPoint()) || $mountPoint->getInternalPath($this->fakeRoot);
+		}));
+	}
+
 	/**
 	 * resolve a path to a storage and internal path
 	 *