After first round of "dcmanager fw-update-strategy apply", remove label from SystemController image by "system --os-region-name SystemController device-image-remove 997d9e44-42e0-4608-b7b6-0f0d37ac6d00 subcloud=t24".
Then upload another image and apply label, did second round of "dcmanager fw-update-strategy apply"".
The issue didn't occur.
Tested on build 2020-08- 06_20-00- 00.
After first round of "dcmanager fw-update-strategy apply", remove label from SystemController image by "system --os-region-name SystemController device-image-remove 997d9e44- 42e0-4608- b7b6-0f0d37ac6d 00 subcloud=t24".
Then upload another image and apply label, did second round of "dcmanager fw-update-strategy apply"".
The issue didn't occur.