We have just identified and fixed a problem with publishing, the symptoms are some or all files are empty on the server, so the site will show up broken or blank.
The explanation is a bit technical, but here goes.
Sparkle is attempting to connect with an encrypted connection generally called “FTP+TLS” using the encryption scheme TLS version 1.3, the server has an implementation that is not compatible with Sparkle’s FTP library (an up to date libcurl, a very common FTP client library). Since it does work with other web hosts and other FTP servers, I strongly suspect the broken implementation is that of some FTP servers, or some specific versions, but it’s not my area of expertise.
Once the connection is set up with the wrong TLS (in Sparkle 2.8.7 or earlier), most file transfers will fail with a “partial transfer” error, generally empty files are “transferred”.
The workaround for now, if you see 0 byte size files on the server, is to manually set the publishing protocol to plain unencrypted “FTP”.
We have addressed this by changing Sparkle’s protocol auto-detection to not go beyond TLS 1.2, but to be manually overridable to TLS 1.3. Coming up soon in the upcoming Sparkle 2.8.8