Error during argocd application diff: Unable to load data: error getting cached app managed resources: cache: key is missing

[Sanjupriya]

Checklist:

• I've searched in the docs and FAQ for my answer: https://bit.ly/argocd-faq.
• I've included steps to reproduce the bug.
• I've pasted the output of argocd version.

Describe the bug

Clicking on diff button in argocd UI intermittently fails with the error:
Unable to load data: error getting cached app managed resources: cache: key is missing

Restarting the argocd-application-controller fixes the issue temporarily, but it reappears after a few days.

To Reproduce

• Deploy an application to ArgoCD
• Click on diff button in ArgoCD UI
• Observe that sometimes the command fails with:

Unable to load data: error getting cached app managed resources: cache: key is missing

• Restart the argocd-application-controller
• Retry clicking diff in argocd UI. It works again

Expected behavior

In argocd UI, clicking diff should consistently load managed resources and display differences without requiring a controller restart.

Screenshots
I currently do not have screenshot of that error

Version

argocd: v2.14.3+71fd4e5
  BuildDate: 2025-02-28T19:57:20Z
  GitCommit: 71fd4e501d0d688ab0d70cd649fbf5f909cff12b
  GitTreeState: clean
  GoVersion: go1.24.0
  Compiler: gc
  Platform: darwin/arm64
argocd-server: v2.14.2+ad27246
  BuildDate: 2025-02-05T23:44:17Z
  GitCommit: ad2724661b66ede607db9b5bd4c3c26491f5be67
  GitTreeState: clean
  GoVersion: go1.23.3
  Compiler: gc
  Platform: linux/arm64
  Kustomize Version: v5.4.3 2024-07-19T16:40:33Z
  Helm Version: v3.16.3+gcfd0749
  Kubectl Version: v0.31.0
  Jsonnet Version: v0.20.0

Logs