The current stable package (net-news/quiterss-0.18.9-r1) does not support Qt 5.11. After upgrading to Qt 5.11, quiterss could no longer update its own database (it was basically frozen - like a snapshot). After upgrading to quiterss-0.18.12, the application worked again.
See also the "main changes" for 0.18.12 on the home page of the package (https://quiterss.org).
x86 stable, closing