SUMMARY When setting Konqueror to show a blank page on new windows/tabs, the Konqueror "about" page shows up in lieu of a blank page. STEPS TO REPRODUCE 1. Settings -> Configure Konqueror. Select "Show Blank Page" next to "When Konqueror Starts"; click OK. 2. Open a new window or tab. OBSERVED RESULT The new window or tab displays the Konqueror about page. EXPECTED RESULT The new window or tab should display a blank page. SOFTWARE/OS VERSIONS KDE Plasma Version: 5.23.0 KDE Frameworks Version: 5.87.0 Qt Version: 5.15.2 Kernel Version: 5.14.12-arch1-1 (64-bit) ADDITIONAL INFORMATION It appears that the issue is caused by a lack of a handler for konq:blank in KonqUrlSchemeHandler::requestStarted() in konq_aboutpage.cpp.
I opened a merge request which should fix this issue: https://invent.kde.org/network/konqueror/-/merge_requests/94