It also seems that

PipelineDecorator.upload_artifact

is not compatible with caching, sadly,

Both use the exact same mechanism of uploading artifacts (i.e. including caching for downloaded artifacts), in terms of caching pipeline components, this is on a component level (i.e. same code/task same arguments, equals cache hit)
What exactly are you getting ? how is it that the "PipelineDecorator.upload_artifact" uploads to a different storage ? is that reproducible ?