diff --git a/packages/app/src/projects/project-settings-target.test.ts b/packages/app/src/projects/project-settings-target.test.ts
index 2962d2b35..610ec94ce 100644
--- a/packages/app/src/projects/project-settings-target.test.ts
+++ b/packages/app/src/projects/project-settings-target.test.ts
@@ -17,4 +17,22 @@ describe("project settings target", () => {
   it("keeps a host-local route valid after the structural key changes", () => {
     expect(findProjectSettingsTarget([project], "host:host-a:project:prj_1234")).toBe(project);
   });
+
+  it("keeps legacy project IDs scoped to their host", () => {
+    const legacyKey = "remote:github.com/acme/app";
+    const unchangedProject = {
+      projectKey: legacyKey,
+      hosts: [{ serverId: "host-a", projectId: legacyKey }],
+    };
+    const changedProject = {
+      projectKey: "remote:github.com/acme/app-fork",
+      hosts: [{ serverId: "host-b", projectId: legacyKey }],
+    };
+
+    const routeKey = resolveProjectSettingsRouteKey(changedProject);
+    expect(routeKey).toBe(`host:host-b:project:${legacyKey}`);
+    expect(findProjectSettingsTarget([unchangedProject, changedProject], routeKey)).toBe(
+      changedProject,
+    );
+  });
 });
diff --git a/packages/app/src/projects/project-settings-target.ts b/packages/app/src/projects/project-settings-target.ts
index 61b62546c..6dc995691 100644
--- a/packages/app/src/projects/project-settings-target.ts
+++ b/packages/app/src/projects/project-settings-target.ts
@@ -1,5 +1,3 @@
-import { resolveProjectGroupKey } from "./project-group-key";
-
 interface ProjectSettingsTarget {
   projectKey: string;
   hosts: ReadonlyArray<{ serverId: string; projectId?: string }>;
@@ -8,7 +6,7 @@ interface ProjectSettingsTarget {
 function resolveHostLocalProjectKey(host: { serverId: string; projectId?: string }): string | null {
   const projectId = host.projectId?.trim();
   if (!projectId) return null;
-  return resolveProjectGroupKey({ serverId: host.serverId, projectId });
+  return `host:${host.serverId}:project:${projectId}`;
 }
 
 export function resolveProjectSettingsRouteKey(project: ProjectSettingsTarget): string {
diff --git a/packages/server/src/server/project-group-key.test.ts b/packages/server/src/server/project-group-key.test.ts
index d40ad0102..ae91fe164 100644
--- a/packages/server/src/server/project-group-key.test.ts
+++ b/packages/server/src/server/project-group-key.test.ts
@@ -57,6 +57,19 @@ describe("deriveProjectGroupKey", () => {
     ).toBe("remote:github.com/getpaseo/paseo");
   });
 
+  test("accepts an SCP-style remote with a bracketed IPv6 host", () => {
+    const rootPath = path.resolve("repo");
+
+    expect(
+      deriveProjectGroupKey({
+        rootPath,
+        remoteUrl: "git@[2001:db8::1]:getpaseo/paseo.git",
+        worktreeRoot: rootPath,
+        mainRepoRoot: null,
+      }),
+    ).toBe("remote:[2001:db8::1]/getpaseo/paseo");
+  });
+
   test("includes the selected path within a repository", () => {
     const worktreeRoot = path.resolve("repo");
     const rootPath = path.join(worktreeRoot, "packages", "app");
diff --git a/packages/server/src/server/project-group-key.ts b/packages/server/src/server/project-group-key.ts
index 25917750c..93144e069 100644
--- a/packages/server/src/server/project-group-key.ts
+++ b/packages/server/src/server/project-group-key.ts
@@ -39,7 +39,7 @@ function deriveRemoteProjectGroupKey(remoteUrl: string | null): string | null {
   let remotePath: string | null = null;
   const scpLike =
     !trimmed.includes("://") && !/^[A-Za-z]:[\\/]/.test(trimmed)
-      ? trimmed.match(/^(?:[^@/:]+@)?([^/:]+):(.+)$/)
+      ? trimmed.match(/^(?:[^@/:]+@)?(\[[^\]]+\]|[^/:]+):(.+)$/)
       : null;
   if (scpLike) {
     host = scpLike[1] ?? null;
diff --git a/packages/server/src/utils/path.test.ts b/packages/server/src/utils/path.test.ts
index 677122398..030d459e8 100644
--- a/packages/server/src/utils/path.test.ts
+++ b/packages/server/src/utils/path.test.ts
@@ -48,6 +48,10 @@ describe("path equivalence", () => {
     );
   });
 
+  test("accepts contained path segments beginning with two dots", () => {
+    expect(getRealpathAwareRelativePath("/repo", "/repo/..tools")).toBe("..tools");
+  });
+
   test.skipIf(process.platform === "win32")(
     "derives the contained suffix from a realpath-equivalent root",
     () => {
diff --git a/packages/server/src/utils/path.ts b/packages/server/src/utils/path.ts
index 8a1a61646..a1f054d03 100644
--- a/packages/server/src/utils/path.ts
+++ b/packages/server/src/utils/path.ts
@@ -96,7 +96,9 @@ function getRelativePathInsideRoot(root: string, candidate: string): string | nu
 
   if (
     comparisonRelative !== "" &&
-    (comparisonRelative.startsWith("..") || platformPath.isAbsolute(comparisonRelative))
+    (comparisonRelative === ".." ||
+      comparisonRelative.startsWith(`..${platformPath.sep}`) ||
+      platformPath.isAbsolute(comparisonRelative))
   ) {
     return null;
   }