diff --git a/src/crypto/index.js b/src/crypto/index.js
index d2b2bc4bf..802d4660a 100644
--- a/src/crypto/index.js
+++ b/src/crypto/index.js
@@ -1330,12 +1330,14 @@ Crypto.prototype.checkOwnCrossSigningTrust = async function({
 
     const seenPubkey = newCrossSigning.getId();
     const masterChanged = this._crossSigningInfo.getId() !== seenPubkey;
+    const masterExistsNotLocallyCached =
+        newCrossSigning.getId() && !crossSigningPrivateKeys.has("master");
     if (masterChanged) {
         logger.info("Got new master public key", seenPubkey);
     }
     if (
         allowPrivateKeyRequests &&
-        (masterChanged || !crossSigningPrivateKeys.has("master"))
+        (masterChanged || masterExistsNotLocallyCached)
     ) {
         logger.info("Attempting to retrieve cross-signing master private key");
         let signing = null;
@@ -1362,6 +1364,15 @@ Crypto.prototype.checkOwnCrossSigningTrust = async function({
     const selfSigningChanged = oldSelfSigningId !== newCrossSigning.getId("self_signing");
     const userSigningChanged = oldUserSigningId !== newCrossSigning.getId("user_signing");
 
+    const selfSigningExistsNotLocallyCached = (
+        newCrossSigning.getId("self_signing") &&
+        !crossSigningPrivateKeys.has("self_signing")
+    );
+    const userSigningExistsNotLocallyCached = (
+        newCrossSigning.getId("user_signing") &&
+        !crossSigningPrivateKeys.has("user_signing")
+    );
+
     const keySignatures = {};
 
     if (selfSigningChanged) {
@@ -1369,7 +1380,7 @@ Crypto.prototype.checkOwnCrossSigningTrust = async function({
     }
     if (
         allowPrivateKeyRequests &&
-        (selfSigningChanged || !crossSigningPrivateKeys.has("self_signing"))
+        (selfSigningChanged || selfSigningExistsNotLocallyCached)
     ) {
         logger.info("Attempting to retrieve cross-signing self-signing private key");
         let signing = null;
@@ -1394,7 +1405,7 @@ Crypto.prototype.checkOwnCrossSigningTrust = async function({
     }
     if (
         allowPrivateKeyRequests &&
-        (userSigningChanged || !crossSigningPrivateKeys.has("user_signing"))
+        (userSigningChanged || userSigningExistsNotLocallyCached)
     ) {
         logger.info("Attempting to retrieve cross-signing user-signing private key");
         let signing = null;
diff --git a/src/webrtc/call.ts b/src/webrtc/call.ts
index bb73bb858..1a270c5ca 100644
--- a/src/webrtc/call.ts
+++ b/src/webrtc/call.ts
@@ -367,7 +367,11 @@ export class MatrixCall extends EventEmitter {
         this.checkForErrorListener();
         try {
             const screenshareConstraints = await getScreenshareContraints(selectDesktopCapturerSource);
-            if (!screenshareConstraints) return;
+            if (!screenshareConstraints) {
+                this.terminate(CallParty.Local, CallErrorCode.NoUserMedia, false);
+                return;
+            }
+
             if (window.electron?.getDesktopCapturerSources) {
                 // We are using Electron
                 logger.debug("Getting screen stream using getUserMedia()...");
@@ -388,6 +392,7 @@ export class MatrixCall extends EventEmitter {
                     "Failed to get screen-sharing stream: ", err,
                 ),
             );
+            this.terminate(CallParty.Local, CallErrorCode.NoUserMedia, false);
         }
         this.type = CallType.Video;
     }