Excel FTP Power Query getting no data on one computer

I have long used the following simple Excel FTP query to populate a Table. As shown in Power Query Editor:

let
    Source = Csv.Document(Web.Contents("ftp://ftp3.interactivebrokers.com/usa.txt"),[Delimiter="|", Columns=9, Encoding=1252, QuoteStyle=QuoteStyle.None])
in
    Source

Suddenly today it gets no data (i.e., “0 rows loaded.”), but a colleague on a different computer at a different location running that same query does get data (~15k rows). Any ideas on how to debug this failure to get data on this one computer? Among the things I have tried:

1. Confirm that I can get that file via FTP from the same computer using Filezilla, suggesting it’s not a firewall problem.
2. Opening ports 20-21 in Windows Defender.
3. Rolled back Office to the Build prior to last week (when Microsoft pushed a new build).