Korganizer doesn't show CalDAV calendar. No errors, just no calendar.

[A. F. Cano]

Hello,

I exported to vcs format from Korganizer 4.4.11 (that does not support
CalDAV) and placed the resulting file in a Radicale server.  Then, set
up multiple versions of Korganizer (5.2.3 - 2 of them, 4.14.1) to access
the "DAV groupware resource".  Entered the proper user, password, URL
(manual configuration) and when I was done all instances fetched the
collections and they now report "Ready".  After clicking the check mark
for the calendar: nothing.

If I copy the file manually to ~/.kde/share/apps/korganizer/std.vcs and
then add a calendar that "Loads data from an iCal file"  all entries
show up as they should.

I've spent hours searching for answers but all I could find was the
standard set-up procedure and no solution to this actual problem.

I have also set up the CardDAV file in the Radicale server and
Kaddressbook finds it, reads it and displays it just fine.

Korganizer 5.2.3 on Debian Stretch/9 (current stable) with KDE
Frameworks 5.28.0, Qt 5.7.1 (built against 5.7.1) and the xcb
windowing system.

Korganizer 4.14.1 on Debian Jessie/8.

What am I missing? I have gone over the bugs for Korganizer (at
bugs.debian.org) but didn't find any about this problem.

Is anyone else uing Korganizer with CalDAV?  With Radicale
specifically?

Any suggestions as to what to try/do to figure what is happening?

Thanks.

Augustine