I used to be able to update from within the Panel.
After receiving the release email, I went straight away to update to 3.25.1 and this message appeared:
Failed to download X3
Warning: file_exists(): open_basedir restriction in effect.
File(/storage/content/01/232401/X3.25.1.update.flat.zip) is not within the allowed path(s): (/storage/content/01/232401/xxx.com/:/storage/configuration/wrappers/01/232401/xxx.com/:/tmp/) in /storage/content/01/232401/xxx.com/public_html/x3_updater.php on line 127 downloaded
I know there is a manual installation option, but I still wanted to report this in case it can be fixed from your side.