diff --git a/apps/files_external/tests/Service/DBConfigServiceTest.php b/apps/files_external/tests/Service/DBConfigServiceTest.php
index d41c2ee31813c..dbc30bd367e98 100644
--- a/apps/files_external/tests/Service/DBConfigServiceTest.php
+++ b/apps/files_external/tests/Service/DBConfigServiceTest.php
@@ -26,6 +26,10 @@ protected function setUp(): void {
 		parent::setUp();
 		$this->connection = Server::get(IDBConnection::class);
 		$this->dbConfig = new DBConfigService($this->connection, Server::get(ICrypto::class));
+		// Remove any mounts left by a previously failed test run
+		foreach ($this->dbConfig->getAllMounts() as $mount) {
+			$this->dbConfig->removeMount($mount['mount_id']);
+		}
 	}
 
 	protected function tearDown(): void {
diff --git a/apps/files_external/tests/Service/StoragesServiceTestCase.php b/apps/files_external/tests/Service/StoragesServiceTestCase.php
index 5eed8294b8f8c..594684e8236f6 100644
--- a/apps/files_external/tests/Service/StoragesServiceTestCase.php
+++ b/apps/files_external/tests/Service/StoragesServiceTestCase.php
@@ -50,6 +50,13 @@ public function clean(): void {
 			$this->removeMount($id);
 		}
 	}
+
+	public function cleanAll(): void {
+		foreach ($this->getAllMounts() as $mount) {
+			$this->removeMount($mount['mount_id']);
+		}
+		$this->mountIds = [];
+	}
 }
 
 #[\PHPUnit\Framework\Attributes\Group(name: 'DB')]
@@ -65,6 +72,7 @@ abstract class StoragesServiceTestCase extends \Test\TestCase {
 	protected function setUp(): void {
 		parent::setUp();
 		$this->dbConfig = new CleaningDBConfig(Server::get(IDBConnection::class), Server::get(ICrypto::class));
+		$this->dbConfig->cleanAll(); // Remove any mounts left by previous test runs
 		self::$hookCalls = [];
 		$config = Server::get(IConfig::class);
 		$this->dataDir = $config->getSystemValue(
diff --git a/apps/files_sharing/tests/Repair/CleanupShareTargetTest.php b/apps/files_sharing/tests/Repair/CleanupShareTargetTest.php
index aaa653135ce4b..1b86a1336bca8 100644
--- a/apps/files_sharing/tests/Repair/CleanupShareTargetTest.php
+++ b/apps/files_sharing/tests/Repair/CleanupShareTargetTest.php
@@ -27,6 +27,11 @@ class CleanupShareTargetTest extends TestCase {
 	protected function setUp(): void {
 		parent::setUp();
 		$this->cleanupShareTarget = Server::get(CleanupShareTarget::class);
+		// Ensure all test users' home folders are in the filecache before any share
+		// operations, because tearDown wipes filecache and getShareById JOINs on it.
+		foreach ([self::TEST_FILES_SHARING_API_USER1, self::TEST_FILES_SHARING_API_USER2, self::TEST_FILES_SHARING_API_USER3] as $user) {
+			$this->rootFolder->getUserFolder($user)->getDirectoryListing();
+		}
 	}
 
 	private function createUserShare(string $by, string $target = self::TEST_FOLDER_NAME): IShare {
diff --git a/lib/private/Files/Storage/Wrapper/Quota.php b/lib/private/Files/Storage/Wrapper/Quota.php
index 11b992dbf9727..a5b4c6ddc5196 100644
--- a/lib/private/Files/Storage/Wrapper/Quota.php
+++ b/lib/private/Files/Storage/Wrapper/Quota.php
@@ -132,10 +132,12 @@ public function fopen(string $path, string $mode) {
 		}
 
 		$source = $this->getWrapperStorage()->fopen($path, $mode);
-		if ($source && (is_int($free) || is_float($free)) && $free >= 0 && $mode !== 'r' && $mode !== 'rb') {
-			// only apply quota for files, not metadata, trash or others
-			if ($this->shouldApplyQuota($path)) {
+		if ($source && $mode !== 'r' && $mode !== 'rb' && $this->shouldApplyQuota($path)) {
+			if ((is_int($free) || is_float($free)) && $free >= 0) {
 				return \OC\Files\Stream\Quota::wrap($source, $free);
+			} elseif ($free === FileInfo::SPACE_NOT_COMPUTED) {
+				// Used space is unknown; apply full quota as a conservative ceiling
+				return \OC\Files\Stream\Quota::wrap($source, $this->getQuota());
 			}
 		}
 
diff --git a/tests/lib/Files/Cache/CacheTest.php b/tests/lib/Files/Cache/CacheTest.php
index 8d62e449306c1..4ff57b6529d56 100644
--- a/tests/lib/Files/Cache/CacheTest.php
+++ b/tests/lib/Files/Cache/CacheTest.php
@@ -801,26 +801,31 @@ public function testExtended(): void {
 		$entries = $this->cache->getFolderContents('');
 		$this->assertCount(4, $entries);
 
-		$this->assertEquals('foo1', $entries[0]->getName());
-		$this->assertEquals('foo2', $entries[1]->getName());
-		$this->assertEquals('foo3', $entries[2]->getName());
-		$this->assertEquals('foo4', $entries[3]->getName());
-
-		$this->assertEquals(20, $entries[0]->getCreationTime());
-		$this->assertEquals(0, $entries[0]->getUploadTime());
-		$this->assertEquals(null, $entries[0]->getMetadataEtag());
-
-		$this->assertEquals(0, $entries[1]->getCreationTime());
-		$this->assertEquals(30, $entries[1]->getUploadTime());
-		$this->assertEquals(null, $entries[1]->getMetadataEtag());
-
-		$this->assertEquals(0, $entries[2]->getCreationTime());
-		$this->assertEquals(0, $entries[2]->getUploadTime());
-		$this->assertEquals('foo', $entries[2]->getMetadataEtag());
-
-		$this->assertEquals(0, $entries[3]->getCreationTime());
-		$this->assertEquals(0, $entries[3]->getUploadTime());
-		$this->assertEquals(null, $entries[3]->getMetadataEtag());
+		// getFolderContentsById has no ORDER BY — index by name to avoid order-dependent assertions
+		$byName = [];
+		foreach ($entries as $entry) {
+			$byName[$entry->getName()] = $entry;
+		}
+		$this->assertArrayHasKey('foo1', $byName);
+		$this->assertArrayHasKey('foo2', $byName);
+		$this->assertArrayHasKey('foo3', $byName);
+		$this->assertArrayHasKey('foo4', $byName);
+
+		$this->assertEquals(20, $byName['foo1']->getCreationTime());
+		$this->assertEquals(0, $byName['foo1']->getUploadTime());
+		$this->assertEquals(null, $byName['foo1']->getMetadataEtag());
+
+		$this->assertEquals(0, $byName['foo2']->getCreationTime());
+		$this->assertEquals(30, $byName['foo2']->getUploadTime());
+		$this->assertEquals(null, $byName['foo2']->getMetadataEtag());
+
+		$this->assertEquals(0, $byName['foo3']->getCreationTime());
+		$this->assertEquals(0, $byName['foo3']->getUploadTime());
+		$this->assertEquals('foo', $byName['foo3']->getMetadataEtag());
+
+		$this->assertEquals(0, $byName['foo4']->getCreationTime());
+		$this->assertEquals(0, $byName['foo4']->getUploadTime());
+		$this->assertEquals(null, $byName['foo4']->getMetadataEtag());
 
 		$this->cache->update($id1, ['upload_time' => 25]);