Steps to reproduce:

1. create one or more templates with no tags
2. send api requests with template.update to replace tag on template (repeat for every created template)
3. api response with no errors

Result:

After this steps, there in no tag on last updated template. If its one template it dont add the tag. If its two, it doesnt add to the last updated.

Expected:
All updated templates contains given tags.

Note: I try the same with tags on host, it works as expected.