> I have not set any options

Are you sure?
The URL points to a file less than 200kb. The default size  limits in httrack
should allow that.

I tried to download the file directly using httrack's default settings and it
worked for me. I am using the same httrack version.

What does it look like on the limits tab?:

<https://www.httrack.com/html/step9_opt2.html>

If the fields are blank, then httrack uses the default limits.

Can you share your project options with us?
Please copy and paste here the content of hts-cache/doit.log and
hts-cache/winprofile.ini.