Hi,
I suspect this might be related to something with WPML as well, since the result URL is perfectly fine on the back-end, and is actually requested from WordPress core, so it should be always correct.
First, please update the plugin to the latest release, to make sure this is not something that had been fixed before (version 4.20.4).
Then, pelase make sure to check these WPML compatibility fixes.
If nothing happens, then please add temporary FTP access as well, I will check the source for possible issues.