Influxdb not saving fields correctly

I convert a json mqtt payload to the following line protocol:
xxxx,participantid=xxx,project=xx,topic=hitlab/xx/xxx/xxxx ecg=21i,timestamp=1696582123.6445334 1696582123678647310

However, in the data explorer I see that influx has created 2 metrics with 1 field instead of 1 metric with 2 fields. Can anyone explain why this is happening?