Problems with curl under macOS Monterey

Question

We have a problem with curl. Under Big Sur, the command

curl 'ftp://ftp.myserver/myPath/my File' -u 'myusername':'mypassword' 
properly downloads the file.

Under Monterey, the same command throws an error:

curl: (3) URL using bad/illegal format or missing URL

The behaviour is the same, whether the command is issued in Terminal, or as a shell script in a Applescript application created in XCode.

Also note that the username/password combo does work, as it does properly download the list of the directory.

Any advice, workaround etc. is highly appreciated.