Chunk length error when using reverse proxy


I am trying to setup InfluxDB in such a way that it is reachable from outside my network. In order to do so Openlitespeed is used to receive requests from Telegraf agents and forward them to the InfluxDB backend.
When I try to use this setup I receive the following errors from the Telegraf agent:

2020-07-20T15:06:10Z E! [outputs.influxdb] When writing to []: 400 Bad Request: invalid byte in chunk length
2020-07-20T15:06:10Z D! [outputs.influxdb] Buffer fullness: 10000 / 10000 metrics
2020-07-20T15:06:10Z E! [agent] Error writing to outputs.influxdb: could not write any address

Influxd reports lines like this:
[httpd] 10.x.x.x,10.x.x.x - influx [20/Jul/2020:17:11:09 +0200] “POST /write?consistency=any&db=telegraf HTTP/1.1” 400 41 “-” “Telegraf/1.14.4” 3e15283b-ca9b-11ea-83e3-000c29625261 41

When trying to connect to the InfluxDB instance directly from the agent everything works as intended. Is there a way to disable chunking in the client? Or any other way to fix this behaviour?