SNMP Table treating all columns as tags?

I’m attempting to collect TCP stats using the TCP-MIB::tcpConnTable data. It pulls the table as expected but all of the columns get inserted as tags, not fields. I tried to add the index_as_tag option but that didn’t fix it.

[[inputs.snmp.table]]        
    oid = "TCP-MIB::tcpConnTable"
    index_as_tag = true
    inherit_tags = ["sysName"]

Influx:

> show tag keys from tcpConnTable
name: tcpConnTable
tagKey
------
agent_host
host
index
sysName
tcpConnLocalAddress
tcpConnLocalPort
tcpConnRemAddress
tcpConnRemPort

I want the tcpConn columns as fields. I suppose I can manually specify them using inputs.snmp.table.field but the documentation says I shouldn’t have to and that they will be automatically added.

By default all columns of the SNMP table will be collected - it is not required to add a nested field for each column, only those which you wish to modify.

Any idea why each item is being seen as a tag instead of field?