Telegraf getting 400 errors

Is this only used for client authentification? Or is this always required to connect to influxdb via https?
According to Telegraf TLS Client Authentication in Influxdb output - #3 by cruscio they are not necessary for TLS usage without client auth.

urls = ["https://influx.some.where:8086"]
# --- SNIP. --- 
  ## Optional TLS Config for use on HTTP connections.
#tls_ca = "/etc/telegraf/ca.pem"
#tls_cert = "/etc/telegraf/cert.pem"
#tls_key = "/etc/telegraf/key.pem"
  ## Use TLS but skip chain & host verification
#insecure_skip_verify = false

I seem to be unable to find appropriate documentation.


I set up a TLS reverse Proxy which works fine for a lot of other services but for influx I keep getting the following:

2018-10-27T15:06:00Z E! [outputs.influxdb] when writing to [https://influx.some.where:8086]: 400 Bad Request
2018-10-27T15:06:00Z E! Error writing to output [influxdb]: could not write any address

Configuration posted here: TLS configuration with telefgraf and influxdb behind nginx proxy TLS Termination endpoint - #2 by drahnr