Warning: Error in curl::new_handle: An unknown option was passed in to libcurl

Not able to publish when using curl 4.3.1 or curl 4.3.2. Error message:
Warning: Error in curl::new_handle: An unknown option was passed in to libcurl

Problem is solved when using curl 4.3.0, but I'm trying to figure out the root cause. Any ideas?

Sounds like an option was changed from curl 4.3.1 and 4.3.0, but I cannot tell without the code or at least the call to curl. However, there looks like there are no changes to the options in 4.3.1 according to the changelog. GitHub curl/NEWS