Helm performs a lookup for the object based on its group (apps), version (v1), and kind (Deployment). Also known as its GroupVersionKind, or GVK. Changing the GVK is considered a compatibility breaker from Kubernetes' point of view, so you cannot "upgrade" those objects to the new GVK in-place. Earlier versions of Helm 3 did not perform the lookup correctly which has since been fixed to match the spec.
In 4dfac075aa the `apiVersion` of the deployment resources was updated to `apps/v1` in tune with the api's deprecated, resulting in compatibility breakage.
Sameer Naik
2154c35a97