Dashboard: How type Tables work

[hikouki-gumo]

I want to build a table dashboard that count total request and error request by span name (a.k.a my API), using trace.
In query builder, I built 3 queries, they differ on has_error filter:

1. No has_error -> Total
2. has_error = true -> Error
3. has_error = false -> Ok

Result:

api/v1/start | n/a | 3 | n/a

In Trace query, I can find total of 5 trace record:

2025-08-01 17:06:12.483 | api/v1/start | 9.63ms | N/A | N/A | true
2025-08-01 17:03:10.564 | api/v1/start | 5.88ms | N/A | N/A | true
2025-08-01 16:59:26.597 | api/v1/start | 0.53ms | N/A | N/A | false
2025-08-01 16:59:19.753 | api/v1/start | 0.51ms | N/A | N/A | false
2025-08-01 16:56:32.198 | api/v1/start | 7.90ms | N/A | N/A | true

What is wrong?

I feel SigNoz really difficult to reasoning. In addition, COUNT return n/a instead of 0, why?