open-socket-for-uri returns string, but integer is needed

[mbcladwell]

Hi,
On Debian 10, Guile 3.0.4 I need to create a socket:

mbc@HP8300:~$ guile
GNU Guile 3.0.4
Copyright (C) 1995-2020 Free Software Foundation, Inc.
Enter `,help' for help.
scheme@(guile-user)> (use-modules (web client))
scheme@(guile-user)> (open-socket-for-uri  
"https://blockchain.info/q/24hrprice";)
$1 = #<input-output: file 7f09b60b0e00>
scheme@(guile-user)> (open-socket-for-uri "http://localhost:3000/123";)
$2 = #<input-output: socket 14>
scheme@(guile-user)>

A local http looks good - returns an integer socket.
A remote https uri returns file 7f09b60b0e00 which is rejected by  
downstream functions requiring a port/integer e.g. (http-get ....  
#:port )

I get the same results on Guile 2.2.7 in a Guix protected environment.
What am I doing wrong - how do I get an integer returned?
Thanks
Mortimer