Changing Tags from uppercase to lowercase ends in

[fmoehler]

When trying to change a tag/tags from uppercase to lowercase the CPI fails with the following issue:
CPI 'set_disk_metadata' method responded with error: CmdError{"type":"Bosh::Clouds::CloudError","message":"AddTags map[key:value] to <Disk-ID> failed: SDK.ServerError\nErrorCode: TagKey.Duplication\nRecommend: https://api.aliyun.com/troubleshoot?q=TagKey.Duplication\u0026product=Ecs\nRequestId: 7399091A-2665-34C0-9AFB-E20F41FF21C9\nMessage: The TagKey has duplication with others, case-insensitive.
It appears to me as if the CPI first tries to add the new tags before deleting the old ones, which results in this error.