syslog-ng spamming logs with HTTP header info since 4.8.2 update

I'm running syslog-ng OSE on Ubuntu 24.04, using the official syslog-ng.com repo. I'm feeding logs to the OpenObserve HTTP destination.

destination d_openobserve_http { openobserve-log( url("https://REDACTED") port(443) organization("default") stream("syslog-ng") user("REDACTED") password("REDACTED") ); }; log { source(s_src); destination(d_openobserve_http); flags(flow-control); }; 

Since a recent update, probably syslog-ng 4.8.2, syslog-ng has started spamming the system log with many lines of debug info for every HTTP call to openobserve

syslog-ng[89285]: * Found bundle for host: 0x7cd07002c0a0 [serially] syslog-ng[89285]: * Can not multiplex, even if we wanted to syslog-ng[89285]: * Re-using existing connection with host REDACTED syslog-ng[89285]: * Server auth using Basic with user 'REDACTED' syslog-ng[89285]: > POST /api/default/syslog-ng/_json HTTP/1.1 syslog-ng[89285]: Host: REDACTED syslog-ng[89285]: Authorization: Basic REDACTED syslog-ng[89285]: User-Agent: syslog-ng 4.8.3/libcurl 8.5.0 syslog-ng[89285]: Accept: */* syslog-ng[89285]: Accept-Encoding: deflate, gzip, br, zstd syslog-ng[89285]: Connection: keep-alive syslog-ng[89285]: Content-Length: 5617 syslog-ng[89285]: Content-Type: application/x-www-form-urlencoded syslog-ng[89285]: syslog-ng[89285]: < HTTP/1.1 200 OK syslog-ng[89285]: < Server: nginx/1.24.0 (Ubuntu) syslog-ng[89285]: < Date: Sat, 24 May 2025 19:43:16 GMT syslog-ng[89285]: < Content-Type: application/json syslog-ng[89285]: < Transfer-Encoding: chunked syslog-ng[89285]: < Connection: keep-alive syslog-ng[89285]: < vary: Origin, Access-Control-Request-Method, Access-Control-Request-Headers syslog-ng[89285]: < vary: accept-encoding 

I've gone over the configuration and I can't find anything that would cause this to suddenly change.

syslog-ng is not running in "verbose" or "debug" mode, according to syslog-ng-ctl.

How do I make it stop logging this info?