Can't get telegraf to write to influxdb v1 database

Telegraf
1

I am trying to write weather data from MQTT to an influxdb v1 database. Using a very simple configuration:

[agent]
omit_hostname = true
debug = true

[[inputs.mqtt_consumer]]
servers = ["tcp://mqttserver:1883"]
topics = ["Weather/#"]
data_format = "value"
data_type = "string"

[[outputs.influxdb]]
urls = ["http://127.0.0.1:8086"]
database = "weather"
exclude_database_tag = false
skip_database_creation = false
exclude_retention_policy_tag = true
username = "XXXXX"
password = "XXXXXX"

[[outputs.file]]
files = ["stdout"]

Running telegraf with debug enabled gives the impression of data being written:

mqtt_consumer,topic=Weather value="wind Dn:028,Dm:153,Dx:290,Sn:0.5,Sm:1.1,Sx:1.8" 1752603293864809253
2025-07-15T18:14:54Z D! [outputs.file] Wrote batch of 2 metrics in 155.744µs
2025-07-15T18:14:54Z D! [outputs.file] Buffer fullness: 0 / 10000 metrics
2025-07-15T18:14:54Z D! [outputs.influxdb] Wrote batch of 2 metrics in 30.306697ms
2025-07-15T18:14:54Z D! [outputs.influxdb] Buffer fullness: 0 / 10000 metrics

but grafana just says “no data”.

Any suggestions?