RTx-Shredder wipeout with incorrect links

Greetings,

When I use the web interface of rtx-shredder - in RT 3.6.5 - to wipeout
tickets, the ‘preview’ links of the tickets that will be wiped out is
pointing to the wrong URL. Maybe the RT_SiteConfig or Apache confs are
incorrect, and I would like some advise.

It shows this URL:
https://rt.mydomain/Ticket/Display.html?id=54563

instead of this:
https://rt.mydomain/rt/Ticket/Display.html?id=54563

RT_SIteConfig relevant lines:
Set($Organization , “mydomain”);
Set($RTAddressRegexp , ‘^rt@rt.mydomain$’);
Set($CanonicalizeEmailAddressMatch , ‘rt.mydomain$’);
Set($CanonicalizeEmailAddressReplace , ‘mydomain’);
Set($CorrespondAddress , ‘rt@rt.mydomain’);
Set($CommentAddress , ‘rt@rt.mydomain’);
Set($WebBaseURL , “https://rt.mydomain”);
Set($WebPath, “/rt”);

Thanks in advance,

Alex