In the screenshot below I am selecting to delete the child application argocd.

When the delete box pops up you can see it is actually going to delete the argocd-bootstrap application which is its parent.

This only happens with application resources.
Thanks for catching it! Fixed by https://github.com/argoproj/argo-cd-ui/commit/98caad1ff707ff4581bbd1b734648f88e79244da
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Thanks for catching it! Fixed by https://github.com/argoproj/argo-cd-ui/commit/98caad1ff707ff4581bbd1b734648f88e79244da