A log message repeating fields from the previous log message

[anilj1]

We have written a logger using zap and the log message contains the fields from the previous log message as well. For example, below are two log lines.

logger.AgentId("agentId").JobId("jobId").Info("This info message")
logger.SiteName("siteName").Info("This info message")

The output from these two log lines is as follows:

{"level":"info","ts":"2022-08-26T18:48:54.427-0700","caller":"testprog/structlogger/logmain.go:21","msg":"This info message","service":"unknownPod","pod":"unknownPod-1","TraceId":"traceId","TenantOrgId":"tenantId","AgentId":"agentId","JobId":"jobId"}

{"level":"info","ts":"2022-08-26T18:48:54.427-0700","caller":"testprog/structlogger/logmain.go:22","msg":"This info message","service":"unknownPod","pod":"unknownPod-1","TraceId":"traceId","TenantOrgId":"tenantId","AgentId":"agentId","JobId":"jobId","SiteName":"siteName"}

The problem is that the second log line repeats the fields "AgentId" and "JobId" whereas it should just print the "SiteName".

I came across an old post (#622) related to this and am not sure what may cause this behavior.