diff --git a/scripts/test-helpers b/scripts/test-helpers
index 7f3f517e10..d1aee3171e 100755
--- a/scripts/test-helpers
+++ b/scripts/test-helpers
@@ -534,8 +534,8 @@ cleanup-test-env(){
       export SERVER_ARGS=''
       export WAIT_SERVICES="${all_services[*]}"
 
-      unset AGENT_1_ARGS AGENT_2_ARGS AGENT_3_ARGS AGENT_DOCKER_ARGS
-      unset SERVER_1_ARGS SERVER_2_ARGS SERVER_3_ARGS SERVER_DOCKER_ARGS
+      unset AGENT_1_ARGS AGENT_2_ARGS AGENT_3_ARGS AGENT_DOCKER_ARGS K3S_IMAGE_AGENT
+      unset SERVER_1_ARGS SERVER_2_ARGS SERVER_3_ARGS SERVER_DOCKER_ARGS K3S_IMAGE_SERVER
 
       unset -f server-pre-hook server-post-hook agent-pre-hook agent-post-hook cluster-pre-hook cluster-post-hook test-post-hook test-cleanup-hook
 }
diff --git a/scripts/test-run-upgrade b/scripts/test-run-upgrade
index 3921eb1d1b..7274d21f77 100755
--- a/scripts/test-run-upgrade
+++ b/scripts/test-run-upgrade
@@ -41,9 +41,11 @@ start-test() {
     kubectl get node -o wide
     kubectl create -f scripts/airgap/volume-test.yaml
 
-    # Add post-hook sleeps to give the kubelet time to update the version after startup
+    # Add post-hook sleeps to give the kubelet time to update the version after startup.
+    # Server gets an extra 60 seconds to handle the metrics-server service being unavailable:
+    # https://github.com/kubernetes/kubernetes/issues/120739
     server-post-hook(){
-        sleep 15
+        sleep 75
     }
     export -f server-post-hook
     agent-post-hook(){